Product Folder Order Now Support & Community Tools & Software Technical Documents LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 LMK0482x Ultra Low-Noise JESD204B Compliant Clock Jitter Cleaner With Dual Loop PLLs 1 Features 2 Applications * * * * * * * 1 * * * * * * * * * * * * * JEDEC JESD204B Support Ultra-Low RMS Jitter - 88 fs RMS Jitter (12 kHz to 20 MHz) - 91 fs RMS Jitter (100 Hz to 20 MHz) - -162.5 dBc/Hz Noise Floor at 245.76 MHz Up to 14 Differential Device Clocks from PLL2 - Up to 7 SYSREF Clocks - Maximum Clock Output Frequency 3.1 GHz - LVPECL, LVDS, HSDS, LCPECL Programmable Outputs from PLL2 Up to 1 Buffered VCXO/Crystal Output from PLL1 - LVPECL, LVDS, 2xLVCMOS Programmable Dual Loop PLLatinumTM PLL Architecture PLL1 - Up to 3 Redundant Input Clocks - Automatic and Manual Switch-Over Modes - Hitless Switching and LOS - Integrated Low-Noise Crystal Oscillator Circuit - Holdover Mode When Input Clocks are Lost PLL2 - Normalized [1 Hz] PLL Noise Floor of -227 dBc/Hz - Phase Detector Rate up to 155 MHz - OSCin Frequency-Doubler - Two Integrated Low-Noise VCOs 50% Duty Cycle Output Divides, 1 to 32 (even and odd) Precision Digital Delay, Dynamically Adjustable 25-ps Step Analog Delay Multi-Mode: Dual PLL, Single PLL, and Clock Distribution Industrial Temperature Range: -40 to 85C Supports 105C PCB Temperature (Measured at Thermal Pad) 3.15-V to 3.45-V Operation Package: 64-Pin QFN (9.0 mm x 9.0 mm x 0.8 mm) Wireless Infrastructure Data Converter Clocking Networking, SONET/SDH, DSLAM Medical / Video / Military / Aerospace Test and Measurement 3 Description The LMK0482x family is the industry's highest performance clock conditioner with JEDEC JESD204B support. The 14 clock outputs from PLL2 can be configured to drive seven JESD204B converters or other logic devices, using device and SYSREF clocks. SYSREF can be provided using both DC and AC coupling. Not limited to JESD204B applications, each of the 14 outputs can be individually configured as highperformance outputs for traditional clocking systems. The high performance, combined with features such as the ability to trade off between power or performance, dual VCOs, dynamic digital delay, holdover, and glitchless analog delay, make the LMK0482x family ideal for providing flexible highperformance clocking trees. Device Information(1) PART NUMBER VCO0 FREQUENCY VCO1 FREQUENCY LMK04821 1930 to 2075 MHz 2920 to 3080 MHz VCO1 Div = /2 to /8 (/2 = 1460 to 1540 MHz) LMK04826 1840 to 1970 MHz 2440 to 2505 MHz LMK04828 2370 to 2630 MHz 2920 to 3080 MHz (1) For all available packages, see the orderable addendum at the end of the datasheet. Simplified Schematic 1 An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications, intellectual property matters and other important disclaimers. PRODUCTION DATA. LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Table of Contents 1 2 3 4 5 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Device Comparison Table..................................... 1 1 1 2 7 6 7 Pin Configuration and Functions ......................... 8 Specifications....................................................... 11 5.1 Device Configuration Information.............................. 7 7.1 7.2 7.3 7.4 7.5 7.6 7.7 8 Absolute Maximum Ratings .................................... ESD Ratings............................................................ Recommended Operating Conditions..................... Thermal Information ................................................ Electrical Characteristics......................................... SPI Interface Timing ............................................... Typical Characteristics - Clock Output AC Characteristics ......................................................... 11 11 11 11 12 25 26 Parameter Measurement Information ................ 28 8.1 Charge Pump Current Specification Definitions...... 28 8.2 Differential Voltage Measurement Terminology ..... 29 9 Detailed Description ............................................ 30 9.1 9.2 9.3 9.4 9.5 Overview ................................................................. Functional Block Diagram ....................................... Feature Description................................................. Device Functional Modes........................................ Programming........................................................... 30 35 39 50 56 9.6 Register Maps ........................................................ 57 9.7 Device Register Descriptions .................................. 61 10 Applications and Implementation.................... 102 10.1 10.2 10.3 10.4 10.5 10.6 10.7 Application Information........................................ Digital Lock Detect Frequency Accuracy ............ Driving CLKin and OSCin Inputs......................... Output Termination and Biasing ......................... Typical Applications ............................................ System Examples .............................................. Do's and Don'ts ................................................... 102 102 103 105 107 110 113 11 Power Supply Recommendations ................... 114 11.1 Pin Connection Recommendations..................... 114 11.2 Current Consumption / Power Dissipation Calculations............................................................ 116 12 Layout................................................................. 117 12.1 Layout Guidelines ............................................... 117 12.2 Layout Example .................................................. 118 13 Device and Documentation Support ............... 119 13.1 13.2 13.3 13.4 13.5 Device Support .................................................. Related Links ...................................................... Trademarks ......................................................... Electrostatic Discharge Caution .......................... Glossary .............................................................. 119 119 119 119 119 14 Mechanical, Packaging, and Orderable Information ......................................................... 119 4 Revision History Changes from Revision AR (December 2015) to Revision AS Page * Deleted references to "LMK0482xB" and replaced with device names ................................................................................. 1 * Updated Pin Configuration and Functions table with expanded descriptions ........................................................................ 8 * Changed mVpp to |mV| for 10-mA HSDS VOD in Electrical Characteristics......................................................................... 22 * Added requirements for OSCout LVPECL emitter resistors to Detailed Description ........................................................... 30 * Changed Overview to provide more detail. .......................................................................................................................... 30 * Changed Three PLL1 Redundant Reference Inputs to provide more detail. ....................................................................... 31 * Changed Frequency Holdover wording for added clarity. .................................................................................................... 31 * Moved VCO1 Divider (LMK04821 only) to within Internal VCOs. ........................................................................................ 31 * Changed all instances of '0-delay' to 'zero-delay' and added reference to Multi-Clock Synchronization app note. ............ 33 * Changed Figure 10 and Figure 11 to show OSCout_MUX, SYNC/SYSREF detail, and color. ........................................... 35 * Changed Figure 13 to show distribution path reclocking, other FB_MUX targets. .............................................................. 38 * Added SYSREF_DDLY_PD and DCLKoutX_DDLY_PD conditions for added power savings in SYNC/SYSREF.............. 39 * Added reference to Recommended Programming Sequence.............................................................................................. 40 * Changed _CNTH/_CNTL register values to 0, representing delay value of 16, in Table 3. ............................................... 43 * Added timing alignment figure, alignment equations to SYSREF to Device Clock Alignment ............................................ 45 * Added LOS register requirements to Input Clock Switching - Automatic Mode................................................................... 47 * Merged redundant paragraph into Digital Lock Detect. ....................................................................................................... 47 * Added note clarifying PLL1 phase detector frequency effect on PLL1_WND_SIZE in Digital Lock Detect......................... 47 * Added holdover entry conditions and clarifications in Holdover. .......................................................................................... 48 * Added Single-Loop Mode, Single-Loop Mode With External VCO, Distribution Mode to Device Functional Modes. ......... 50 2 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Revision History (continued) * Added RESET Pin to Recommended Programming Sequence........................................................................................... 56 * Changed CLKoutX_Y_ODL, CLKoutX_Y_IDL, DCLKoutX_DIV descriptions to add more detail. ....................................... 63 * Changed DCLKoutX_ADLY description in DCLKoutX_ADLY, DCLKoutX_ADLY_MUX, DCLKout_MUX........................... 64 * Changed SDCLKoutY_ADLY description in SDCLKoutY_ADLY_EN, SDCLKoutY_ADLY. ................................................ 65 * Added OSCout LVPECL format instructions in VCO_MUX, OSCout_MUX, OSCout_FMT. ............................................... 68 * Changed SYSREF_CLR description in SYSREF_CLR, SYNC_1SHOT_EN, SYNC_POL, SYNC_EN, SYNC_PLL2_DLD, SYNC_PLL1_DLD, SYNC_MODE to add more detail.......................................................................... 74 * Added time alongside frequency for LOS_TIMEOUT in Table 45 ....................................................................................... 80 * Changed LOS_EN description to clarify requirements in Table 45...................................................................................... 80 * Changed Table 53, Table 55, Table 56 register text from "N counter" to "R divider" .......................................................... 84 * Changed Table 57 maximum field value to match register size........................................................................................... 85 * Changed Table 75 headers from Resistance to Capacitance. .......................................................................................... 96 * Changed Application Information to reference current TI tools. ......................................................................................... 102 * Changed all images in Driving CLKin and OSCin Inputs to include OSCin. ..................................................................... 103 * Changed CLKinX_BUF_TYPE to CLKinX_TYPE in Driving CLKin and OSCin Pins With a Single-Ended Source. ......... 104 * Added Output Termination and Biasing section. ................................................................................................................ 105 * Changed Typical Applications to reference up-to-date tools.............................................................................................. 107 * Added System Examples .................................................................................................................................................. 110 * Added OSCout, LVDS/HSDS, and RESET pin recommendations to Do's and Don'ts. ..................................................... 113 * Added Pin Connection Recommendations ........................................................................................................................ 114 * Deleted empty column in Table 87 and redirected to TICS Pro current calculator. ........................................................... 116 * Changed tools listed in Device Support . ........................................................................................................................... 119 Changes from Revision AQ (August 2014) to Revision AR Page * Added Support for 105C thermal pad temperature............................................................................................................... 1 * Changed from I/O to I for pin 6 in Pin Functions table. ......................................................................................................... 8 * Deleted programmable status pin in Description column for pin 6 in Pin Functions table. .................................................... 8 * Changed from No connection to Do not connect for pins 7, 8, 9 in Pin Functions table. ..................................................... 9 * Changed to Reference Clock Input Port 1 for PLL 1 for Pins 34, 35 in Pin Functions. ........................................................ 9 * Added Reference Clock Input Port 2 for PLL1 for pins 40, 41 in Pin Functions. ................................................................ 10 * Added ESD Ratings.............................................................................................................................................................. 11 * Added PCB temperature in Recommended Operating Conditions. ..................................................................................... 11 * Added Digital Input Timing in Electrical Characteristics. ..................................................................................................... 24 * Changed Detailed block diagrams for LMK04821 and LMK04826/8. ................................................................................. 35 * Added 6 to DCLKout0 sequence and 7 to SDCLKout1 sequence in Figure 12................................................................... 37 * Added 6 to DCLKout0 sequence and 7 to SDCLKout1 sequence in Figure 13................................................................... 38 * Added For each SDCLKoutY being used in SYNC/SYSREF............................................................................................... 39 * Deleted "SDCLKoutY_PD as required per output. " in Table 1............................................................................................ 39 * Added footnote starting SDCLKoutY_PD = 0 as... in Table 1. ............................................................................................ 39 * Added SDCLKout1_PD = 0, SDCLKout3_PD = 0 in Setup of SYSREF Example............................................................... 40 * Changed DLD_HOLD_CNT to HOLDOVER_DLD_CNT in Holdover Mode - Automatic Exit of Holdover . ........................ 49 * Changed Recommended Programming Sequence. ............................................................................................................ 56 * Added 0x171/0x172 to Register Map. ................................................................................................................................. 60 * Added LMK04821 register setting. ....................................................................................................................................... 62 * Revised Register 0x143 table............................................................................................................................................... 74 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 3 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com * Added fixed register setting for 0x171.................................................................................................................................. 75 * Added fixed register setting for 0x172 ................................................................................................................................. 75 * Added LMK04821 register setting. ...................................................................................................................................... 98 * Added LMK04821 register setting. ...................................................................................................................................... 99 * Changed RB_PLL1_LD description. .................................................................................................................................... 99 * Changed RB_PLL2_LD description. .................................................................................................................................... 99 Changes from Revision AP (June 2013) to Revision AQ Page * Changed data sheet flow and layout to conform with new TI standards. Added, updated, or renamed the following sections: Device Information Table, Application and Implementation; Power Supply Recommendations; Layout; Device and Documentation Support; Mechanical, Packaging, and Ordering Information .................................................... 1 * Added values for LMK04821 under "Features" section. ........................................................................................................ 1 * Changed LMK04820 family to LMK0482x family. ................................................................................................................. 1 * Added values for LMK04821 in Device Configuration Information......................................................................................... 7 * Added holdover DAC to pin 36 description in Pin Functions. ............................................................................................... 9 * Changed Thermal Information header from LMK0482xB to LMK0482x. ............................................................................ 11 * Changed CLKinX_BUF_TYPE to CLKinX_TYPE in Electrical Characteristics. ................................................................... 12 * Added values for LMK04821 under Internal VCO Specifications in Electrical Characteristics. ........................................... 15 * Added values for LMK04821 under Noise Floor in Electrical Characteristics. ..................................................................... 16 * Added values for LMK04821 under CLKout Closed Loop Phase Noise Specifications a Commercial Quality VCXO in Electrical Characteristics. ................................................................................................................................................. 17 * Added 245.76 MHz as frequency for LMK04826B phase noise data L(f)CLKout for VCO0. .................................................. 18 * Added 245.76 MHz as frequency for LMK04826B phase noise data L(f)CLKout for VCO1. .................................................. 18 * Added 245.76 MHz as frequency for LMK04828B phase noise data L(f)CLKout for VCO0. .................................................. 18 * Added 245.76 MHz as frequency for LMK04828B phase noise data L(f)CLKout for VCO1. .................................................. 18 * Added values for LMK04821 under CLKout Closed Loop Jitter Specifications a Commercial Quality VCXO. ................... 19 * Added SDCLKoutY_HS = 0 for tsJESD204B in Electrical Characteristics. ............................................................................... 21 * Added Propagation Delay from CLKin0 to SDCLKoutY in Electrical Characteristics........................................................... 21 * Added footnote that LMK04821 has no DCLKoutX or SDCLKoutY outputs on at power up, only OSCout. ...................... 21 * Changed VOH TEST CONDITIONS to = 3 or 4 and VOL TEST CONDITIONS to 3, 4, or 6 under DIGITAL OUTPUTS (CLKin_SELX, Status_LDX, and RESET/GPO) subheading in Electrical Characteristics. .................................................. 23 * Changed Digital Inputs (SCK, SDIO, CS*) IIH VIH = VCC min line from 5 A to -5 A........................................................ 24 * Added 4 wire mode read back has same timing as SDIO pin, R/W bit = 0 is for SPI write, R/W bit = 1 is for SPI read, W1 and W0 shall be written as 0. ............................................................................................................................... 25 * Added LMK04821 phase noise graphs under Clock Output AC Characteristics. ................................................................ 26 * Added link to AN-912 Application Report. ............................................................................................................................ 29 * Changed from Glitchless Half Shift to Glitchless Half Step.................................................................................................. 33 * Added LMK04821 detailed block diagram............................................................................................................................ 35 * Changed block from SDCLKoutY_POL to DCLKoutX_POL in Figure 12. ........................................................................... 37 * Added SYSREF_CLKin0_MUX block to Figure 13 image. .................................................................................................. 38 * Changed Figure 13 to show that FB_MUX SYSREF input comes from SYSREF Divider, not SYSREF_MUX. ................. 38 * Changed term pulsor to pulser throughout........................................................................................................................... 39 * Changed DCLKout0_1_DIV to DCLKout0_DIV; DCLKout2_3_DIV to DCLKout2_DIV; DCLKout4_5_DIV to DCLKout4_DIV. .................................................................................................................................................................... 40 * Added DCLKout4_DIV = 20. ................................................................................................................................................ 40 * Added DCLKout0_DDLY_PD = 0, DCLKout2_DDLY_PD = 0, DCLKout4_DDLY_PD = 0. ................................................. 40 * Changed text to read, Set device clock and SYSREF divider digital delays: DCLKout0_DDLY_CNTH, DCLKout0_DDLY_CNTL, DCLKout2_DDLY_CNTH, DCLKout2_DDLY_CNTL, DCLKout4_DDLY_CNTH, 4 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 DCLKout4_DDLY_CNTL, SYSREF_DDLY. ........................................................................................................................ 40 * Added = 1 in SYSREF Request. ......................................................................................................................................... 41 * Changed step numbers in dynamic delay and references to steps to be correct, step 8 was duplicated. ......................... 44 * Added note LMK04821 includes VCO1 divider on VCO1 output.. ....................................................................................... 50 * Added note LMK04821 includes VCO1 divider on VCO1 output.. ....................................................................................... 51 * Added R/W bit = 0 is for SPI write. R/W bit = 1 is for SPI read. ......................................................................................... 56 * Added If using LMK04821, program register 0x174 in Recommended Programming Sequence. ..................................... 56 * Added SYSREF_CLKin0_MUX and VCO1_DIV to register map. ........................................................................................ 58 * Added CLKin_OVERRIDE bit to register map. .................................................................................................................... 59 * Changed from half shift to half step...................................................................................................................................... 64 * Changed definition of SDCLKoutY_DDLY value of 0 from Reserved to Bypass. ................................................................ 64 * Changed from Sets the polarity of SYSREF clocks to Sets the polarity of clock on SDCLKoutY when device clock output is selected with SDCLKoutY_MUX............................................................................................................................ 67 * Changed Sets the polarity of the device clocks to Sets the polarity of the device clocks from the DCLKoutX outputs. ..... 67 * Added LMK04821 DCLKoutX_FMT power on reset values as powerdown......................................................................... 67 * Changed from SYSREF to SYSREF Divider in Source column of Register 0x13F. ........................................................... 71 * Changed reserved to Off for CLKin1_OUT_MUX. .............................................................................................................. 76 * Changed reserved to Off for CLKin0_OUT_MUX. .............................................................................................................. 76 * Added CLKin_OVERRIDE bit. .............................................................................................................................................. 83 * Added LMK04821 register 0x174 for VCO1_DIV................................................................................................................. 98 * Deleted LMK04828 from Core line. ................................................................................................................................... 116 * Added VCO1 Icc including VCO1 Divider for LMK04821................................................................................................... 116 * Changed VCO1 Icc and power dissipated for LMK04828B/26B from 6 mA to 13.5 mA and 19.8 mW to 44.55 mW. ...... 116 Changes from Revision AO (March 2013) to Revision AP Page * Changed datasheet title from LMK04828 to LMK0482xB ...................................................................................................... 1 * Changed LMK04828 family to LMK04820 family. .................................................................................................................. 1 * Changed image from LMK04828B to LMK0482xB. ............................................................................................................... 1 * Added LMK04826 to Device Configuration Information table. ............................................................................................... 7 * Changed - increased LMK04828B VCO0 max frequency from 2600 MHz to 2630 MHz. ..................................................... 7 * Changed - expanded LMK04828B VCO1 frequency range from 2945 - 3005 MHz to 2920 MHz - 3080 MHz..................... 7 * Changed Thermal Information header from LMK04828B to LMK0482xB............................................................................ 11 * Added LMK04826 VCO Range Specification ....................................................................................................................... 15 * Changed - increased LMK04828B VCO0 max frequency from 2600 MHz to 2630 MHz. ................................................... 15 * Changed - expanded LMK04828B VCO1 frequency range from 2945 - 3005 MHz to 2920 MHz - 3080 MHz................... 15 * Added LMK04826 KVCO specification. .................................................................................................................................. 15 * Added clarification of LMK04828 specification vs LMK04826 specification for KVCO. .......................................................... 15 * Added LMK04826 noise floor data. ...................................................................................................................................... 16 * Changed - clarified phase noise data section header. ......................................................................................................... 17 * Added LMK04826 phase noise data. ................................................................................................................................... 18 * Added LMK04826 jitter data. ................................................................................................................................................ 19 * Added LMK04826 fCLKout-startup spec. ..................................................................................................................................... 21 * Added clarification of LMK04828 specification vs. LMK04826 specification for fCLKout-startup. ................................................ 21 * Added LMK04826B Phase Noise Performance Graph for VCO0. ....................................................................................... 26 * Added LMK04826B Phase Noise Performance Graph for VCO1. ....................................................................................... 26 * Added Added PLL2 loop filter bandwidth and phase margin info to plot. ............................................................................ 27 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 5 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com * Changed LMK04828 to LMK0482xB in VCXO/Crystal Buffered Output. ............................................................................ 31 * Changed LMK04828 to LMK0482xB in Status Pins. ........................................................................................................... 33 * Changed image from LMK04828 to LMK0482xB................................................................................................................. 50 * Changed - corrected value of PLL2_P selection to be 0 to correspond with register programming definition. ................... 50 * Changed image from LMK04828 to LMK0482xB................................................................................................................. 51 * Changed image from LMK04828 to LMK0482xB................................................................................................................. 52 * Added LMK04826 register setting. ....................................................................................................................................... 62 * Added LMK04826 register setting. ....................................................................................................................................... 98 * Added LMK04826 register setting. ....................................................................................................................................... 99 6 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 5 Device Comparison Table 5.1 Device Configuration Information PART NUMBER REFERENCE INPUTS (1) OSCout (BUFFERED OSCin Clock) LVDS/ LVPECL/ LVCMOS (1) PLL2 PROGRAMMABLE LVDS/LVPECL/HSDS OUTPUTS VCO0 FREQUENCY VCO1 FREQUENCY VCO1_DIV = /2 1460 to 1540 MHz VCO1_DIV = /3 974 to 1026 MHz VCO1_DIV = /4 730 to 770 MHz LMK04821 Up to 3 Up to 1 14 1930 to 2075 MHz VCO1_DIV = /5 584 to 616 MHz VCO1_DIV = /6 487 to 513 MHz VCO1_DIV = /7 418 to 440 MHz VCO1_DIV = /8 365 to 385 MHz (1) LMK04826 Up to 3 Up to 1 14 1840 to 1970 MHz 2440 to 2505 MHz LMK04828 Up to 3 Up to 1 14 2370 to 2630 MHz 2920 to 3080 MHz OSCout may also be third clock input, CLKin2. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 7 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 6 Pin Configuration and Functions NKD Package 64-Pin WQFN Top View CLKin_SEL1 SDCLKout11* SDCLKout11 DCLKout10* DCLKout10 Vcc11_CG3 DCLKout8* DCLKout8 SDCLKout9* SDCLKout9 57 56 55 54 53 52 51 50 49 SDCLKout13 60 CLKin_SEL0 SDCLKout13* 61 58 DCLKout12 62 59 Vcc12_CG0 DCLKout12* 63 Clock Group 3 64 Clock Group 0 DCLKout0 1 48 Status_LD2 DCLKout0* 2 47 Vcc10_PLL2 CPout2 SDCLKout1 3 46 SDCLKout1* 4 45 Vcc9_CP2 RESET/GPO 5 44 OSCin* SYNC/SYSREF_REQ 6 43 OSCin NC 7 42 Vcc8_OSCin NC 8 41 OSCout*/CLKin2* LLP-64 Top down view NC 9 40 OSCout/CLKin2 Vcc1_VCO 10 39 Vcc7_OSCout LDObyp1 11 38 CLKin0* LDObyp2 12 37 CLKin0 SDCLKout3 13 36 Vcc6_PLL1 SDCLKout3* 14 35 CLKin1*/Fin*/FBCLKin* DCLKout2 15 34 CLKin1/Fin/FBCLKin DCLKout2* 16 33 Vcc5_DIG 23 24 25 26 27 28 29 30 SDCLKout5* DCLKout4 DCLKout4* Vcc4_CG2 DCLKout6 DCLKout6* SDCLKout7 SDCLKout7* 32 22 SDCLKout5 CPout1 21 Vcc3_SYSREF 31 20 Status_LD1 19 SCK 18 CS* Clock Group 1 SDIO 17 Vcc2_CG1 DAP Clock Group 2 Pin Functions PIN NO. 1 I/O (1) DCLKout0 2 DCLKout0* 3 SDCLKout1 4 SDCLKout1* 5 RESET/GPO 6 SYNC/SYSREF_REQ (1) (2) 8 DESCRIPTION (2) NAME O Device clock output 0. Differential clock output. Part of clock group 0. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. O SYSREF / Device clock output 1. Differential clock output. Part of clock group 0. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. I/O Device reset input or GPO. If used as a reset input, pin polarity and nominal 160-k pull-up or pull-down are controlled by register settings. If used as an output, can be set to push-pull or open-drain. I Synchronization input.. Can be used to reset dividers, trigger the SYSREF pulser, or request continuous SYSREF from the SYSREF divider. Pin polarity is controlled by register settings. Nominal 160-k pulldown. The definitions below define the I/O type for each pin. (a) I = Input (b) O = Output (c) I/O = Input / Output (Configurable) (d) P = Power Supply (e) BP = Bypass (LDO output) (f) G = Ground (g) NC = No Connect See Pin Connection Recommendations for recommended connections. Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Pin Functions (continued) PIN NO. I/O (1) DESCRIPTION (2) NAME 7, - NC 8 - NC 9 - NC 10 Vcc1_VCO 11 LDObyp1 BP LDO bypass. This pin must be bypassed to ground with 10-F capacitor placed close to the pin. 12 LDObyp2 BP LDO bypass.This pin must be bypassed to ground with a 0.1-F capacitor placed close to the pin. 13, SDCLKout3 O 14 SDCLKout3* SYSREF / Device clock output 3. Differential clock output. Part of clock group 1. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 15 DCLKout2 O 16 DCLKout2* Device clock output 2. Differential clock output. Part of clock group 1. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 17 Vcc2_CG1 P Power supply for clock outputs 2 and 3. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. 18 CS* I SPI Chip select. Active-low input. Must be pulled up externally or actively driven high when not in use. 19 SCK I SPI clock. Active-high input. Nominal 160-k pulldown. 20 SDIO I/O 21 Vcc3_SYSREF 22 SDCLKout5 23 SDCLKout5* 24 DCLKout4 25 DCLKout4* 26 Vcc4_CG2 27 DCLKout6 28 DCLKout6* 29 SDCLKout7 30 SDCLKout7* 31 P Do not connect. These pins must be left floating. Power supply for VCO LDO. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. SPI data. This pin can implement bidirectional I/O. As an output, this pin can be configured for open-drain or push-pull. Open-drain output requires external pull-up. Register settings can disable the output feature of this pin. Other GPIO pins can also be configured as SPI MISO (master-in slave-out) for traditional 4-wire SPI. P Power supply for SYSREF divider and SYNC. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. O SYSREF / Device clock output 5. Differential clock output. Part of clock group 2. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. O Device clock output 4. Differential clock output. Part of clock group 2. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. Power supply for clock outputs 4, 5, 6, and 7. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. O Device clock output 6. Differential clock output. Part of clock group 2. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. O SYSREF / Device clock output 7. Differential clock output. Part of clock group 2. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. Status_LD1 I/O Programmable status pin. By default, this pin is configured as an active-high output representing the state of PLL1 lock detect. Other status conditions and output polarity are register-selectable. This pin can be configured for open-drain or push-pull output. 32 CPout1 O Charge pump 1 output. This pin is connected to the external loop filter components for PLL1, and to the VCXO control voltage pin. 33 Vcc5_DIG P Power supply for digital circuitry, such as SPI bus and GPIO pins. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. CLKin1 I (Default) Reference clock input port 1 for PLL1. Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. FBCLKin I Feedback input for external clock feedback input (zero-delay mode). Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. Fin I External VCO input (external VCO mode) or Clock Distribution input (distribution mode). Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. CLKin1* I (Default) Reference clock input port 1 for PLL1. Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. FBCLKin* I Feedback input for external clock feedback input (zero-delay mode). Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. Fin* I External VCO input (external VCO mode) or Clock Distribution input (distribution mode). Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. 36 Vcc6_PLL1 P Power supply for PLL1, charge pump 1, holdover DAC. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. 37 CLKin0 I Reference clock input port 0 for PLL1. Can also be used as a synchronization input for SYNC/SYSREF. Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. 34 35 38 CLKin0* Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 9 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Pin Functions (continued) PIN NO. 39 I/O (1) DESCRIPTION (2) NAME Vcc7_OSCout P Power supply for OSCout port and CLKin2. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. (Default) Buffered output of OSCin port. Defaults to LVPECL. In LVPECL output format, this pin only supports 240- emitter resistors. If unused, set output format buffer to powerdown and leave pins floating. OSCout CLKin2 Reference clock input port 2 for PLL1. Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. Registers must be configured to set this pin as an input. OSCout* (Default) Buffered output of OSCin port. Defaults to LVPECL. In LVPECL output format, this pin only supports 240- emitter resistors. If unused, set output format buffer to powerdown and leave pins floating. 40 I/O 41 I/O CLKin2* Reference clock input port 2 for PLL1. Can be configured for DC or AC coupling. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. Registers must be configured to set this pin as an input. P Power supply for OSCin. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. I Feedback to PLL1, reference input to PLL2. Inputs to this pin should be AC-coupled. Accepts single-ended or differential clocks. If unused in single-ended configuration, connect to GND with a 0.1-F capacitor. Leave floating if both pins are unused. See Driving CLKin and OSCin Inputs for single-ended termination information. Vcc9_CP2 P Power supply for PLL2 charge pump. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. 46 CPout2 O Charge pump 2 output. This pin is connected to the external components of the PLL2 loop filter. If an external VCO is used, this pin is also connected to the external VCO control voltage pin. Do not route this pin near noisy signals. 47 Vcc10_PLL2 P Power supply for PLL2. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. 48 Status_LD2 I/O Programmable status pin. By default, this pin is configured as an active-high output representing the state of PLL2 lock detect. Other status conditions and output polarity are register-selectable. This pin can be configured for open-drain or push-pull output. 49 SDCLKout9 O 50 SDCLKout9* SYSREF / Device clock 9. Differential clock output. Part of clock group 3. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 51 DCLKout8 O 52 DCLKout8* Device clock output 8. Differential clock output. Part of clock group 3. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 53 Vcc11_CG3 P Power supply for clock outputs 8, 9, 10, and 11. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. 54 DCLKout10 O 55 DCLKout10* Device clock output 10. Differential clock output. Part of clock group 3. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 56 SDCLKout11 O 57 SDCLKout11* SYSREF / Device clock output 11. Differential clock output. Part of clock group 3. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 58 CLKin_SEL0 I/O Programmable status pin. By default this pin is programmed as an active-high input with nominal 160-k pulldown that selects which CLKin is used as the reference to PLL1 in pin-select mode. If used as an input, pin polarity and nominal 160-k pull-up or pull-down are controlled by register settings. If used as an output, can be set to push-pull or opendrain. 59 CLKin_SEL1 I/O Programmable status pin. By default this pin is programmed as an active-high input with nominal 160-k pulldown that selects which CLKin is used as the reference to PLL1 in pin-select mode. If used as an input, pin polarity and nominal 160-k pull-up or pull-down are controlled by register settings. If used as an output, can be set to push-pull or opendrain. 60 SDCLKout13 O 61 SDCLKout13* SYSREF / Device clock output 13. Differential clock output. Part of clock group 0. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 62 DCLKout12 O 63 DCLKout12* Device clock output 12. Differential clock output. Part of clock group 0. To minimize noise, keep all outputs in the clock group at the same frequency, or at frequencies without spurious interference. If unused, set output format buffer to powerdown and leave pins floating. 64 Vcc12_CG0 P Power supply for clock outputs 0, 1, 12, and 13. Decoupling capacitance requirements may change with system frequency. See Pin Connection Recommendations for recommendations. - DAP G Die attach pad. Connect directly to GND plane through multiple vias to minimize resistive and inductive effects and to achieve good thermal performance. All power supply pins are referred to the DAP ground. 42 Vcc8_OSCin 43 OSCin 44 OSCin* 45 10 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 7 Specifications 7.1 Absolute Maximum Ratings over operating free-air temperature range (unless otherwise noted) (1) MIN MAX UNIT -0.3 3.6 V -0.3 (VCC + 0.3) V Lead temperature (solder 4 seconds) 260 C TJ Junction temperature 150 C IIN Differential input current (CLKinX/X*, OSCin/OSCin*, FBCLKin/FBCLKin*, Fin/Fin*) 5 mA MSL Moisture sensitivity level Tstg Storage temperature VCC Supply voltage VIN Input voltage TL (1) (2) (2) 3 -65 150 C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. Never to exceed 3.6 V. 7.2 ESD Ratings VALUE V(ESD) (1) (2) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001 (1) 2000 Machine Model (MM) 150 Charged-device model (CDM), per JEDEC specification JESD22C101 (2) 250 UNIT V JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 500-V HBM is possible with the necessary precautions. Pins listed as 2000 V may actually have higher performance. JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process. Manufacturing with less than 250-V CDM is possible with the necessary precautions. Pins listed as 250 V may actually have higher performance. 7.3 Recommended Operating Conditions over operating free-air temperature range (unless otherwise noted) TJ Junction temperature TA Ambient temperature TPCB PCB temperature (measured at thermal pad) VCC Supply voltage MIN TYP -40 25 3.15 3.3 MAX UNIT 125 C 85 C 105 C 3.45 V 7.4 Thermal Information LMK0482x THERMAL METRIC (1) NKD (WQFN) UNIT 64 PINS RJA Junction-to-ambient thermal resistance (2) RJC(top) Junction-to-case (top) thermal resistance RJB Junction-to-board thermal resistance (4) (1) (2) (3) (4) (3) 24.3 C/W 6.1 C/W 3.5 C/W For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report (SPRA953). The junction-to-ambient thermal resistance under natural convection is obtained in a simulation on a JEDEC-standard, High-K board, as specified in JESD51-7, in an environment described in JESD51-2a. The junction-to-case(top) thermal resistance is obtained by simulating a cold plate test on the package top. No specific JEDEC-standard test exists, but a close description can be found in the ANSI SEMI standard G30-88. The junction-to-board thermal resistance is obtained by simulating in an environment with a ring cold plate fixture to control the PCB temperature, as described in JESD51-8. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 11 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Thermal Information (continued) LMK0482x THERMAL METRIC (1) NKD (WQFN) UNIT 64 PINS JT Junction-to-top characterization parameter (5) 0.1 C/W JB Junction-to-board characterization parameter (6) 3.5 C/W RJC(bot) Junction-to-case (bottom) thermal resistance (7) 0.7 C/W (5) (6) (7) The junction-to-top characterization parameter, JT, estimates the junction temperature of a device in a real system and is extracted from the simulation data for obtaining RJA, using a procedure described in JESD51-2a (sections 6 and 7). The junction-to-board characterization parameter, JB estimates the junction temperature of a device in a real system and is extracted from the simulation data for obtaining RJA , using a procedure described in JESD51-2a (sections 6 and 7). The junction-to-case(bottom) thermal resistance is obtained by simulating a cold plate test on the exposed (power) pad. No specific JEDEC standard test exists, but a close description can be found in the ANSI SEMI standard G30-88. 7.5 Electrical Characteristics (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 1 3 mA 565 665 mA 750 MHz CURRENT CONSUMPTION ICC_PD Power down supply current ICC_CLKS Supply current 14 HSDS 8-mA clocks enabled PLL1 and PLL2 locked. (1) CLKin0/0*, CLKin1/1*, and CLKin2/2* INPUT CLOCK SPECIFICATIONS fCLKin Clock input frequency SLEWCLKin Clock input slew rate VIDCLKin Clock input Differential input voltage Figure 8 VSSCLKin 0.001 (2) 20% to 80% (3) Clock input Single-ended input voltage VCLKin 0.15 0.5 V/ns 0.125 1.55 |V| 0.25 3.1 Vpp AC coupled to CLKinX; CLKinX* AC coupled to ground CLKinX_TYPE = 0 (bipolar) 0.25 2.4 Vpp AC coupled to CLKinX; CLKinX* AC coupled to ground CLKinX_TYPE = 1 (MOS) 0.35 2.4 Vpp AC coupled Each pin AC coupled, CLKin0/1/2 CLKinX_TYPE = 0 (bipolar) 0 |mV| Each pin AC coupled, CLKin0/1 CLKinX_TYPE = 1 (MOS) 55 |mV| DC offset voltage between CLKin2/CLKin2* (CLKin2* - CLKin2) Each pin AC coupled CLKinX_TYPE = 1 (MOS) 20 |mV| VCLKin- VIH High input voltage VCLKin- VIL Low input voltage DC coupled to CLKinX; CLKinX* AC coupled to ground CLKinX_TYPE = 1 (MOS) |VCLKinX-offset| DC offset voltage between CLKinX/CLKinX* (CLKinX* - CLKinX) 2.0 VCC V 0.0 0.4 V 0.001 750 MHz 0.001 3100 MHz FBCLKin/FBCLKin* and Fin/Fin* INPUT SPECIFICATIONS fFBCLKin fFin (1) (2) (3) (4) 12 Clock input frequency for zero-delay with external feedback. AC coupled CLKinX_TYPE = 0 (bipolar) Clock input frequency for external VCO or distribution mode (4) AC coupled CLKinX_TYPE = 0 (bipolar) See the applications section of Power Supply Recommendations for Icc for specific part configuration and how to calculate Icc for a specific design. To meet the jitter performance listed in the subsequent sections of this data sheet, the minimum recommended slew rate for all input clocks is 0.5 V/ns. This is especially true for single-ended clocks. Phase-noise performance begins to degrade as the clock input slew rate is reduced. However, the device will function at slew rates down to the minimum listed. When compared to single-ended clocks, differential clocks (LVDS, LVPECL) are less susceptible to degradation in phase-noise performance at lower slew rates, due to their common-mode noise rejection. However, TI also recommends using the highest possible slew rate for differential clocks to achieve optimal phase-noise performance at the device outputs. See Differential Voltage Measurement Terminology for definition of VID and VOD voltages. Assured by characterization. ATE tested at 2949.12 MHz. Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER VFBCLKin/Fin Single ended Clock input voltage SLEWFBCLKin/Fin Slew rate on CLKin (2) TEST CONDITIONS MIN AC coupled CLKinX_TYPE = 0 (bipolar) 0.25 AC coupled; 20% to 80%; (CLKinX_TYPE = 0) 0.15 TYP MAX UNIT 2.0 Vpp 0.5 V/ns PLL1 SPECIFICATIONS fPD1 PLL1 phase detector frequency ICPout1SOURCE ICPout1SINK PLL1 charge Pump source current PLL1 charge Pump sink current (5) 40 VCPout1 = VCC/2, PLL1_CP_GAIN = 0 50 VCPout1 = VCC/2, PLL1_CP_GAIN = 1 150 VCPout1 = VCC/2, PLL1_CP_GAIN = 2 250 ... (5) MHz A ... VCPout1 = VCC/2, PLL1_CP_GAIN = 14 1450 VCPout1 = VCC/2, PLL1_CP_GAIN = 15 1550 VCPout1=VCC/2, PLL1_CP_GAIN = 0 -50 VCPout1=VCC/2, PLL1_CP_GAIN = 1 -150 VCPout1=VCC/2, PLL1_CP_GAIN = 2 -250 ... A ... VCPout1=VCC/2, PLL1_CP_GAIN = 14 -1450 VCPout1=VCC/2, PLL1_CP_GAIN = 15 -1550 ICPout1%MIS Charge pump Sink / source mismatch VCPout1 = VCC/2, T = 25 C 1% ICPout1VTUNE Magnitude of charge pump current variation vs. charge pump voltage 0.5 V < VCPout1 < VCC - 0.5 V TA = 25 C 4% ICPout1%TEMP Charge pump current vs. temperature variation ICPout1 TRI Charge pump TRI-STATE leakage current PN10kHz PLL 1/f noise at 10-kHz offset. Normalized to 1-GHz output frequency PN1Hz Normalized phase noise contribution 10% 4% 0.5 V < VCPout < VCC - 0.5 V 5 PLL1_CP_GAIN = 350 A -117 PLL1_CP_GAIN = 1550 A -118 PLL1_CP_GAIN = 350 A dBc/Hz -221.5 PLL1_CP_GAIN = 1550 A nA dBc/Hz -223 PLL2 REFERENCE INPUT (OSCin) SPECIFICATIONS (6) fOSCin PLL2 reference input SLEWOSCin PLL2 reference clock minimum slew rate on OSCin (2) 20% to 80% VOSCin Input voltage for OSCin or OSCin* AC coupled; single-ended (unused pin AC coupled to GND) VIDOSCin VSSOSCin Differential voltage swing Figure 8 AC coupled |VOSCin-offset| DC offset voltage between OSCin/OSCin* (OSCinX* - OSCinX) Each pin AC coupled fdoubler_max (5) (6) (7) (8) Doubler input frequency 500 (7) 0.15 0.5 MHz V/ns 0.2 2.4 0.2 1.55 |V| 0.4 3.1 Vpp 20 Vpp |mV| (8) EN_PLL2_REF_2X = 1 ; OSCin duty cycle 40% to 60% 155 MHz This parameter is programmable. FOSCin maximum frequency assured by characterization. Production tested at 122.88 MHz. Assured by characterization. ATE tested at 122.88 MHz. The EN_PLL2_REF_2X bit enables or disables a frequency doubler mode for the PLL2 OSCin path. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 13 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 40 MHz CRYSTAL OSCILLATOR MODE SPECIFICATIONS FXTAL Crystal frequency range Fundamental mode crystal ESR = 200 (10 to 30 MHz) ESR = 125 (30 to 40 MHz) CIN Input capacitance of OSCin port -40 to 85 C 10 1 pF PLL2 PHASE DETECTOR and CHARGE PUMP SPECIFICATIONS fPD2 Phase detector frequency (7) 155 VCPout2=VCC/2, PLL2_CP_GAIN = 0 ICPoutSOURCE ICPoutSINK PLL2 charge pump source current PLL2 charge pump sink current (5) (5) VCPout2=VCC/2, PLL2_CP_GAIN = 1 400 VCPout2=VCC/2, PLL2_CP_GAIN = 2 1600 VCPout2=VCC/2, PLL2_CP_GAIN = 3 3200 VCPout2=VCC/2, PLL2_CP_GAIN = 0 -100 VCPout2=VCC/2, PLL2_CP_GAIN = 1 -400 VCPout2=VCC/2, PLL2_CP_GAIN = 2 -1600 VCPout2=VCC/2, PLL2_CP_GAIN = 3 -3200 ICPout2%MIS Charge pump sink/source mismatch ICPout2VTUNE Magnitude of charge pump current vs. 0.5 V < VCPout2 < VCC - 0.5 V charge pump voltage variation TA = 25 C 4% ICPout2%TEMP Charge pump current vs. temperature variation 4% ICPout2TRI Charge pump leakage PN10kHz PLL 1/f noise at 10-kHz offset Normalized to 1-GHz output frequency PN1Hz 1% 0.5 V < VCPout2 < VCC - 0.5 V (9) . Normalized phase noise contribution (10) VCPout2=VCC/2, TA = 25 C A A 10% 10 PLL2_CP_GAIN = 400 A -118 PLL2_CP_GAIN = 3200 A -121 PLL2_CP_GAIN = 400 A -222.5 PLL2_CP_GAIN = 3200 A MHz 100 -227 nA dBc/Hz dBc/Hz (9) A specification in modeling PLL in-band phase noise is the 1/f flicker noise, LPLL_flicker(f), which is dominant close to the carrier. Flicker noise has a 10-dB/decade slope. PN10kHz is normalized to a 10-kHz offset and a 1-GHz carrier frequency. PN10kHz = LPLL_flicker(10 kHz) - 20log(Fout / 1 GHz), where LPLL_flicker(f) is the single side band phase noise of only the flicker noise's contribution to total noise, L(f). To measure LPLL_flicker(f), it is important to be on the 10-dB/decade slope close to the carrier. A high compare frequency and a clean crystal are important to isolating this noise source from the total phase noise, L(f). LPLL_flicker(f) can be masked by the reference oscillator performance if a low power or noisy source is used. The total PLL in-band phase noise performance is the sum of LPLL_flicker(f) and LPLL_flat(f). (10) A specification modeling PLL in-band phase noise. The normalized phase noise contribution of the PLL, LPLL_flat(f), is defined as: PN1HZ=LPLL_flat(f) - 20log(N) - 10log(fPDX). LPLL_flat(f) is the single side band phase noise measured at an offset frequency, f, in a 1-Hz bandwidth and fPDX is the phase-detector frequency of the synthesizer. LPLL_flat(f) contributes to the total noise, L(f). 14 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT INTERNAL VCO SPECIFICATIONS LMK04821 VCO tuning range fVCO LMK04826 VCO tuning range LMK04828 VCO tuning range LMK04821 fine tuning sensitivity KVCO LMK04826 fine tuning sensitivity LMK04828 fine tuning sensitivity |TCL| Allowable temperature drift for continuous lock (12) VCO0 1930 2075 VCO1 (11) 2920 3080 VCO0 1840 1970 VCO1 2440 2505 VCO0 2370 2630 VCO1 2920 3080 LMK04821 VCO0 12 to 20 LMK04821 VCO1 15 to 24 LMK04826 VCO0 11 to 19 LMK04826 VCO1 8 to 11 LMK04828 VCO0 at 2457.6 MHz 17 to 27 LMK04828 VCO1 at 2949.12 MHz 17 to 23 After programming for lock, no changes to output configuration are permitted to assure continuous lock MHz MHz MHz MHz/V MHz/V MHz/V 125 C (11) The VCO1 divider, VCO1_DIV in register 0x174, can be programmed to /2 to /8 resulting in a lower effective VCO frequency range, as shown in Device Configuration Information. (12) Maximum allowable temperature drift for continuous lock is how far the temperature can drift in either direction from the value it was at the time that the 0x168 register was last programmed with PLL2_FCAL_DIS = 0, and still have the part stay in lock. The action of programming the 0x168 register, even to the same value, activates a frequency calibration routine. This implies the part will work over the entire frequency range, but if the temperature drifts more than the maximum allowable drift for continuous lock, then it is necessary to reload the appropriate register to ensure it stays in lock. Regardless of what temperature the part was initially programmed at, the temperature can never drift outside the frequency range of -40 C to 85 C without violating specifications. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 15 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT NOISE FLOOR LVDS L(f)CLKout LMK04821, VCO0, noise floor 20-MHz offset (13) 245.76 MHz -158.2 HSDS 6 mA -160 HSDS 8 mA -161 HSDS 10 mA -161.4 LVPECL16 with 240 -161.6 LVPECL20 with 240 -162 LVPECL 161.7 LVDS -157.1 HSDS 6 mA -158.3 HSDS 8 mA L(f)CLKout L(f)CLKout L(f)CLKout LMK04821, VCO1, noise floor 20-MHz offset (13) LMK04826, VCO0, noise floor 20-MHz offset (14) LMK04826, VCO1, noise floor 20-MHz offset (14) 245.76 MHz 245.76 MHz 245.76 MHz dBc/Hz -159 HSDS 10 mA -159.2 LVPECL16 with 240 -158.8 LVPECL20 with 240 -158.9 LVPECL -158.8 LVDS -158.1 HSDS 6 mA -159.7 HSDS 8 mA -160.8 HSDS 10 mA -161.3 LVPECL16 with 240 -161.8 LVPECL20 with 240 -162.0 LCPECL -161.7 LVDS -157.5 HSDS 6 mA -158.9 HSDS 8 mA -159.8 HSDS 10 mA -160.3 LVPECL16 with 240 -160.8 LVPECL20 with 240 -160.7 LCPECL -160.7 dBc/Hz dBc/Hz dBc/Hz (13) Data collected using a Prodyn BIB-100G balun. Loop filter is C1 = 47 pF, C2 = 3.9 nF, R2 = 620 , C3 = 10 pF, R3 = 200 , C4 = 10 pF, R4 = 200 , PLL1_CP = 450 A, PLL2_CP = 3.2 mA.. VCO0 PLL2 loop filter bandwidth = 288 kHz, phase margin = 72 degrees. VCO1 Loop filter loop bandwidth = 221 kHz, phase margin = 70 degrees. CLKoutX_Y_IDL = 1, CLKoutX_Y_ODL = 0. (14) Data collected using a Prodyn BIB-100G balun. Loop filter for PLL2 is C1 = 47 pF, C2 = 3.9 nF, R2 = 620 , C3 = 10 pF, R3 = 200 , C4 = 10 pF, R4 = 200 , PLL1_CP = 450 A, PLL2_CP = 3.2 mA.. VCO0 loop filter bandwidth = 303 kHz, phase margin = 73 degrees. VCO1 Loop filter loop bandwidth = 151 kHz, phase margin = 64 degrees. CLKoutX_Y_IDL = 1, CLKoutX_Y_ODL = 0. 16 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT NOISE FLOOR (continued) L(f)CLKout L(f)CLKout LMK04828, VCO0, noise floor 20-MHz offset (15) LMK04828, VCO1, noise floor 20-MHz offset (15) 245.76 MHz 245.76 MHz LVDS -156.3 HSDS 6 mA -158.4 HSDS 8 mA -159.3 HSDS 10 mA -158.9 LVPECL16 with 240 -161.6 LVPECL20 with 240 -162.5 LCPECL -162.1 LVDS -155.7 HSDS 6 mA -157.5 HSDS 8 mA -158.1 HSDS 10 mA -157.7 LVPECL16 with 240 -160.3 LVPECL20 with 240 -161.1 LCPECL -160.8 dBc/Hz dBc/Hz CLKout CLOSED LOOP PHASE NOISE SPECIFICATIONS a COMMERCIAL QUALITY VCXO (16) L(f)CLKout LMK04821 VCO0 SSB phase noise 245.76 MHz Offset = 1 kHz -126.9 Offset = 10 kHz -133.5 Offset = 100 kHz -135.4 Offset = 1 MHz (13) Offset = 10 MHz L(f)CLKout LMK04821 VCO1 SSB phase noise 245.76 MHz (13) -149.8 LVDS -158.1 HSDS 8 mA -161.1 LVPECL16 with 240 -161.7 Offset = 1 kHz -126.8 Offset = 10 kHz -133.4 Offset = 100 kHz -135.4 Offset = 1 MHz -151.8 Offset = 10 MHz LVDS -157.2 HSDS 8 mA -159.1 LVPECL16 with 240 -158.9 dBc/Hz dBc/Hz (15) Data collected using ADT2-1T+ balun. Loop filter is C1 = 47 pF, C2 = 3.9 nF, R2 = 620 , C3 = 10 pF, R3 = 200 , C4 = 10 pF, R4 = 200 , PLL1_CP = 450 A, PLL2_CP = 3.2 mA.. VCO0 loop filter bandwidth = 344 kHz, phase margin = 73 degrees. VCO1 Loop filter loop bandwidth = 233 kHz, phase margin = 70 degrees. CLKoutX_Y_IDL = 1, CLKoutX_Y_ODL = 0. (16) VCXO used is a 122.88-MHz Crystek CVHD-950-122.880. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 17 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT CLKout CLOSED LOOP PHASE NOISE SPECIFICATIONS a COMMERCIAL QUALITY VCXO (continued) Offset = 10 kHz -134.8 Offset = 100 kHz L(f)CLKout LMK04826 VCO0 SSB phase noise 245.76 MHz Offset = 1 MHz (14) Offset = 10 MHz -135.4 LVDS -148.2 HSDS 8 mA LVPECL16 with 240 -148.6 LVDS -157.8 HSDS 8 mA -160.4 LVPECL16 with 240 -161.5 Offset = 10 kHz -134.3 Offset = 100 kHz L(f)CLKout LMK04826 VCO1 SSB phase noise 245.76 MHz Offset = 1 MHz (14) Offset = 10 MHz L(f)CLKout LMK04828 VCO0 SSB phase noise 245.76 MHz (15) L(f)CLKout LMK04828 VCO1 SSB phase noise 245.76 MHz (15) Submit Documentation Feedback -152.5 HSDS 8 mA LVPECL16 with 240 -153.6 LVDS -157.3 HSDS 8 mA -159.6 LVPECL16 with 240 -160.5 -124.3 Offset = 10 kHz -134.7 Offset = 100 kHz -136.5 Offset = 1 MHz -148.4 LVDS -156.4 HSDS 8 mA -159.1 LVPECL16 with 240 -160.8 Offset = 1 kHz -124.2 Offset = 10 kHz -134.4 Offset = 100 kHz -135.2 Offset = 1 MHz Offset = 10 MHz 18 -133.7 LVDS Offset = 1 kHz Offset = 10 MHz dBc/Hz -151.5 LVDS -159.9 HSDS 8 mA -155.8 LVPECL16 with 240 -158.1 dBc/Hz dBc/Hz dBc/Hz Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT CLKout CLOSED LOOP JITTER SPECIFICATIONS a COMMERCIAL QUALITY VCXO (16) LMK04821, VCO0 fCLKout = 245.76-MHz integrated RMS jitter (13) JCLKout LMK04821, VCO1 fCLKout = 245.76-MHz integrated RMS jitter (13) LVDS, BW = 12 kHz to 20 MHz 99 HSDS 8 mA, BW = 12 kHz to 20 MHz 94 LVPECL16 with 240 , BW = 12 kHz to 20 MHz 96 LVPECL20 with 240 , BW = 12 kHz to 20 MHz 94 LCPECL with 240 , BW = 12 kHz to 20 MHz 93 LVDS, BW = 12 kHz to 20 MHz 96 HSDS 8 mA, BW = 12 kHz to 20 MHz 90 LVPECL16 with 240 , BW = 12 kHz to 20 MHz 92 LVPECL20 with 240 , BW = 12 kHz to 20 MHz 91 fs rms fs rms LCPECL with 240 , BW = 12 kHz to 20 MHz 91 CLKout CLOSED LOOP JITTER SPECIFICATIONS a COMMERCIAL QUALITY VCXO (continued) LMK04826, VCO0 fCLKout = 245.76-MHz integrated RMS jitter (14) JCLKout LMK04826, VCO1 fCLKout = 245.76-MHz integrated RMS jitter (14) (16) LVDS, BW = 100 Hz to 20 MHz 106 LVDS, BW = 12 kHz to 20 MHz 104 HSDS 8 mA, BW = 100 Hz to 20 MHz 99 HSDS 8 mA, BW = 12 kHz to 20 MHz 97 LVPECL16 /w 240 , BW = 100 Hz to 20 MHz 99 LVPECL16 /w 240 , BW = 12 kHz to 20 MHz 96 LCPECL /w 240 , BW = 100 Hz to 20 MHz 100 LCPECL /w 240 , BW = 12 kHz to 20 MHz 97 LVDS, BW = 100 Hz to 20 MHz 99 LVDS, BW = 12 kHz to 20 MHz 97 HSDS 8 mA, BW = 100 Hz to 20 MHz 92 HSDS 8 mA, BW = 12 kHz to 20 MHz 90 LVPECL16 /w 240 , BW = 100 Hz to 20 MHz 91 LVPECL20 /w 240 , BW = 12 kHz to 20 MHz 89 LCPECL /w 240 , BW = 100 Hz to 20 MHz 92 LCPECL /w 240 , BW = 12 kHz to 20 MHz 89 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback fs rms fs rms 19 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT CLKout CLOSED LOOP JITTER SPECIFICATIONS a COMMERCIAL QUALITY VCXO (continued) (16) LMK04828, VCO0 fCLKout = 245.76-MHz integrated RMS jitter (15) JCLKout LMK04828, VCO1 fCLKout = 245.76-MHz integrated RMS jitter (15) 20 Submit Documentation Feedback LVDS, BW = 100 Hz to 20 MHz 112 LVDS, BW = 12 kHz to 20 MHz 109 HSDS 8 mA, BW = 100 Hz to 20 MHz 102 HSDS 8 mA, BW = 12 kHz to 20 MHz 99 LVPECL16 /w 240 , BW = 100 Hz to 20 MHz 98 LVPECL20 /w 240 , BW = 12 kHz to 20 MHz 95 LCPECL /w 240 , BW = 100 Hz to 20 MHz 96 LCPECL /w 240 , BW = 12 kHz to 20 MHz 93 LVDS, BW = 100 Hz to 20 MHz 108 LVDS, BW = 12 kHz to 20 MHz 105 HSDS 8 mA, BW = 100 Hz to 20 MHz 98 HSDS 8 mA, BW = 12 kHz to 20 MHz 94 LVPECL16 /w 240 , BW = 100 Hz to 20 MHz 93 LVPECL20 /w 240 , BW = 12 kHz to 20 MHz 90 LCPECL /w 240 , BW = 100 Hz to 20 MHz 91 LCPECL /w 240 , BW = 12 kHz to 20 MHz 88 fs rms fs rms Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT DEFAULT POWER on RESET CLOCK OUTPUT FREQUENCY fCLKout-startup Default output clock frequency at device power on (17) (18) LMK04826 235 LMK04828 315 fOSCout OSCout frequency (7) MHz 500 MHz CLOCK SKEW and DELAY DCLKoutX to SDCLKoutY FCLK = 245.76 MHz, RL= 100 AC coupled (19) Same pair, same format (20) SDCLKoutY_MUX = 0 (device clock) Maximum DCLKoutX or SDCLKoutY to DCLKoutX or SDCLKoutY FCLK = 245.76 MHz, RL= 100 AC coupled Any pair, same format (20) SDCLKoutY_MUX = 0 (device clock) SYSREF to device clock setup time base reference. See SYSREF to Device Clock Alignment to adjust SYSREF to device clock setup time as required. SDCLKoutY_MUX = 1 (SYSREF) SYSREF_DIV = 30 SYSREF_DDLY = 8 (global) SDCLKoutY_DDLY = 1 (2 cycles, local) DCLKoutX_MUX = 1 (Div+DCC+HS) DCLKoutX_DIV = 30 DCLKoutX_DDLY_CNTH = 7 DCLKoutX_DDLY_CNTL = 6 DCLKoutX_HS = 0 SDCLKoutY_HS = 0 -80 ps tPDCLKin0_ SDCLKout1 Propagation delay from CLKin0 to SDCLKout1 CLKin0_OUT_MUX = 0 (SYSREF mux) SYSREF_CLKin0_MUX = 1 (CLKin0) SDCLKout1_PD = 0 SDCLKout1_DDLY = 0 (bypass) SDCLKout1_MUX = 1 (SR) EN_SYNC = 1 LVPECL16 /w 240 0.65 ns fADLYmax Maximum analog delay frequency DCLKoutX_MUX = 4 1536 MHz 395 |mV| |TSKEW| tsJESD204B 25 |ps| 50 LVDS CLOCK OUTPUTS (DCLKoutX, SDCLKoutY, and OSCout) VOD Differential output voltage VOD Change in magnitude of VOD for complementary output states VOS Output offset voltage VOS Change in VOS for complementary output states T = 25 C, DC measurement AC coupled to receiver input RL = 100- differential termination -60 1.125 60 1.25 1.375 35 mV V |mV| Output rise time 20% to 80%, RL = 100 , 245.76 MHz Output fall time 80% to 20%, RL = 100 ISA ISB Output short circuit current - single ended Single-ended output shorted to GND T = 25 C -24 24 mA ISAB Output short circuit current differential Complimentary outputs tied together -12 12 mA TR / TF 180 ps (17) OSCout oscillates at start-up at the frequency of the VCXO attached to the OSCin port. (18) LMK04821 has no DCLKoutX or SDCLKoutY outputs which oscillate at power on. Only OSCout oscillates at power on. (19) Equal loading and identical clock output configuration on each clock output is required for specification to be valid. Specification not valid for delay mode. (20) LVPECL uses a 120- emitter resistor, LVDS and HSDS uses a 560- shunt. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 21 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT 6-mA HSDS CLOCK OUTPUTS (DCLKoutX and SDCLKoutY) VCC 1.05 VOH T = 25 C, DC measurement Termination = 50 to VCC - 1.42 V VOL VOD Differential output voltage VOD Change in VOD for complementary output states VCC 1.64 590 -80 |mV| 80 mVpp 8-mA HSDS CLOCK OUTPUTS (DCLKoutX and SDCLKoutY) TR / T F Output rise time 245.76 MHz, 20% to 80%, RL = 100 Output fall time 245.76 MHz, 80% to 20%, RL = 100 170 VCC 1.26 VOH T = 25 C, DC measurement Termination = 50 to VCC - 1.64 V VOL VOD Differential output voltage VOD Change in VOD for complementary output states ps VCC -2.06 800 -115 |mV| 115 mVpp 10-mA HSDS CLOCK OUTPUTS (DCLKoutX and SDCLKoutY) VCC 0.99 VOH T = 25 C, DC measurement Termination = 50 to VCC - 1.43 V VOL VCC 1.97 VOD VOD 980 Change in VOD for complementary output states -115 |mv| 115 mVpp LVPECL CLOCK OUTPUTS (DCLKoutX and SDCLKoutY) 20% to 80% output rise TR / TF 80% to 20% output fall time RL = 100 , emitter resistors = 240 to GND DCLKoutX_TYPE = 4 or 5 (1600 or 2000 mVpp) 150 ps VCC 1.04 V VCC 1.80 V 1600-mVpp LVPECL CLOCK OUTPUTS (DCLKoutX and SDCLKoutY) VOH Output high voltage VOL Output low voltage VOD Output voltage Figure 9 DC measurement Termination = 50 to VCC - 2.0 V 760 |mV| 2000-mVpp LVPECL CLOCK OUTPUTS (DCLKoutX and SDCLKoutY) VOH Output high voltage VOL Output low voltage VOD Output voltage Figure 9 DC measurement Termination = 50 to VCC - 2.3 V VCC 1.09 V VCC 2.05 V 960 |mV| 1.57 V 0.62 V 950 |mV| LCPECL CLOCK OUTPUTS (DCLKoutX and SDCLKoutY) VOH Output high voltage VOL Output low voltage VOD Output voltage Figure 9 22 Submit Documentation Feedback DC measurement Termination = 50 to 0.5 V Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT LVCMOS CLOCK OUTPUTS (OSCout) fCLKout Maximum frequency (21) 5-pF load 250 MHz VOH Output high voltage 1-mA load VOL Output low voltage 1-mA load IOH Output high current (source) VCC = 3.3 V, VO = 1.65 V 28 mA IOL Output low current (sink) VCC = 3.3 V, VO = 1.65 V 28 mA DUTYCLK Output duty cycle (22) VCC/2 to VCC/2, FCLK = 100 MHz, T = 25 C TR Output rise time 20% to 80%, RL = 50 , CL = 5 pF 400 ps TF Output fall time 80% to 20%, RL = 50 , CL = 5 pF 400 ps VCC 0.1 V 0.1 V 50% DIGITAL OUTPUTS (CLKin_SELX, Status_LDX, and RESET/GPO) VOH VOL High-level output voltage IOH = -500 A CLKin_SELX_TYPE = 3 or 4 Status_LDX_TYPE = 3 or 4 RESET_TYPE = 3 or 4 Low-level output voltage IOL = 500 A CLKin_SELX_TYPE = 3, 4, or 6 Status_LDX_TYPE = 3, 4, or 6 RESET_TYPE = 3, 4, or 6 VCC 0.4 V 0.4 V DIGITAL OUTPUT (SDIO) VOH High-level output voltage IOH = -500 A ; During SPI read. SDIO_RDBK_TYPE = 0 VOL Low-level output voltage IOL = 500 A ; During SPI read. SDIO_RDBK_TYPE = 0 or 1 VCC 0.4 V 0.4 V VCC V 0.4 V DIGITAL INPUTS (CLKinX_SEL, RESET/GPO, SYNC, SCK, SDIO, or CS*) VIH High-level input voltage VIL Low-level input voltage 1.2 DIGITAL INPUTS (CLKinX_SEL) IIH IIL High-level input current VIH = VCC Low-level input current VIL = 0 V CLKin_SELX_TYPE = 0, (high impedance) -5 5 CLKin_SELX_TYPE = 1 (pull-up) -5 5 CLKin_SELX_TYPE = 2 (pull-down) 10 80 CLKin_SELX_TYPE = 0, (high impedance) -5 5 -40 -5 CLKin_SELX_TYPE = 2 (pull-down) -5 5 RESET_TYPE = 2 (pull-down) 10 80 CLKin_SELX_TYPE = 1 (pull-up) A A DIGITAL INPUT (RESET/GPO) IIH High-level input current VIH = VCC IIL Low-level input current VIL = 0 V RESET_TYPE = 0 (high impedance) RESET_TYPE = 1 (pull-up) RESET_TYPE = 2 (pull-down) -5 5 -40 -5 -5 5 A A DIGITAL INPUTS (SYNC) IIH High-level input current VIH = VCC IIL Low-level input current VIL = 0 V 25 -5 5 A DIGITAL INPUTS (SCK, SDIO, CS*) (21) Assured by characterization. ATE tested to 10 MHz. (22) Assumes OSCin has 50% input duty cycle. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 23 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Electrical Characteristics (continued) (3.15 V < VCC < 3.45 V, -40 C < TA < 85 C and TPCB 105 C. Typical values at VCC = 3.3 V, TA = 25 C, at the Recommended Operating Conditions and are not assured.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT IIH High-level input current VIH = VCC -5 5 A IIL Low-level input current VIL = 0 -5 5 A RESET pin held high for device reset 25 DIGITAL INPUT TIMING tHIGH 24 Submit Documentation Feedback ns Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 7.6 SPI Interface Timing TEST CONDITIONS MIN TYP MAX UNIT tds Setup time for SDI edge to SCLK rising edge See Figure 1 10 ns tdH Hold time for SDI edge from SCLK rising edge See Figure 1 10 ns tSCLK Period of SCLK See Figure 1 50 (1) ns tHIGH High width of SCLK See Figure 1 25 ns tLOW Low width of SCLK See Figure 1 25 ns tcs Setup time for CS* falling edge to SCLK rising edge See Figure 1 10 ns tcH Hold time for CS* rising edge from SCLK rising edge See Figure 1 30 tdv SCLK falling edge to valid read back data See Figure 1 (1) ns 20 ns 20 MHz Register programming information on the SDIO pin is clocked into a shift register on each rising edge of the SCK signal. On the rising edge of the CS* signal, the register is sent from the shift register to the register addressed. A slew rate of at least 30 V/s is recommended for these signals. After programming is complete, the CS* signal should be returned to a high state. If the SCK or SDIO lines are toggled while the VCO is in lock, as is sometimes the case when these lines are shared with other parts, the phase noise may be degraded during this programming. 4-wire mode read back has same timing as the SDIO pin. R/W bit = 0 is for SPI write. R/W bit = 1 is for SPI read. W1 and W0 are written as 0. SDIO (WRITE) R/W W1 tdS tdH tcS tHIGH W0 A12 to A0, D7 to D2 D1 D0 SCLK tcH tLOW tSCLK SDIO (Read) D7 to D2 tdV D1 D0 Data valid only during read CS* Figure 1. SPI Timing Diagram Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 25 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 7.7 Typical Characteristics - Clock Output AC Characteristics These plots show performance at frequencies beyond the point at which the part is ensured to operate, to give an idea of the capabilities of the part. They do not imply any sort of ensured specification. For Figure 2 through Figure 7, CLKout2_3_IDL=1; CLKout2_3_ODL=0; LVPECL20 with 240- emitter resistors; DCLKout2 Frequency = 245.76 MHz; DCLKout2_MUX = 0 (Divider). For Figure 2 through Figure 5, Balun Prodyn BIB-100G. For Figure 6 and Figure 7, Balun ADT2-1T+. VCO_MUX = 0 (VCO0) VCO0 = 1966.08 MHz DCLKout2_DIV = 8 PLL2 Loop Filter Bandwidth = 288 kHz PLL2 Phase Margin = 72 Figure 2. LMK04821 DCLKout2 Phase Noise VCO_MUX = 0 (VCO0) VCO0 = 1966.08 MHz DCLKout2_DIV = 8 PLL2 Loop Filter Bandwidth = 303 kHz PLL2 Phase Margin = 73 Figure 4. LMK04826 DCLKout2 Phase Noise 26 Submit Documentation Feedback VCO_MUX = 1 (VCO1) VCO = 2949.12 MHz DCLKout2_DIV = 6 VCO1_DIV = 0 (/2) PLL2 Loop Filter Bandwidth = 221 kHz PLL2 Phase Margin = 70 Figure 3. LMK04821 DCLKout2 Phase Noise VCO_MUX = 1 (VCO1) VCO = 2457.6 MHz DCLKout2_DIV = 10 PLL2 Loop Filter Bandwidth = 151 kHz PLL2 Phase Margin = 64 Figure 5. LMK04826 DCLKout2 Phase Noise Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Typical Characteristics - Clock Output AC Characteristics (continued) These plots show performance at frequencies beyond the point at which the part is ensured to operate, to give an idea of the capabilities of the part. They do not imply any sort of ensured specification. For Figure 2 through Figure 7, CLKout2_3_IDL=1; CLKout2_3_ODL=0; LVPECL20 with 240- emitter resistors; DCLKout2 Frequency = 245.76 MHz; DCLKout2_MUX = 0 (Divider). For Figure 2 through Figure 5, Balun Prodyn BIB-100G. For Figure 6 and Figure 7, Balun ADT2-1T+. VCO_MUX = 0 (VCO0) VCO0 = 2457.6 MHz DCLKout2_DIV = 10 PLL2 Loop Filter Bandwidth = 344 kHz PLL2 Phase Margin = 73 Figure 6. LMK04828 DCLKout2 Phase Noise VCO_MUX = 1 (VCO1) VCO = 2949.12 MHz DCLKout2_DIV = 12 PLL2 Loop Filter Bandwidth = 233 kHz PLL2 Phase Margin = 70 Figure 7. LMK04828 DCLKout2 Phase Noise Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 27 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 8 Parameter Measurement Information 8.1 Charge Pump Current Specification Definitions I1 = Charge Pump Sink Current at VCPout = VCC - V I2 = Charge Pump Sink Current at VCPout = VCC/2 I3 = Charge Pump Sink Current at VCPout = V I4 = Charge Pump Source Current at VCPout = VCC - V I5 = Charge Pump Source Current at VCPout = VCC/2 I6 = Charge Pump Source Current at VCPout = V V = Voltage offset from the positive and negative supply rails. Defined to be 0.5 V for this device. 8.1.1 Charge Pump Output Current Magnitude Variation Vs. Charge Pump Output Voltage 8.1.2 Charge Pump Sink Current Vs. Charge Pump Output Source Current Mismatch 8.1.3 Charge Pump Output Current Magnitude Variation Vs. Ambient Temperature 28 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 8.2 Differential Voltage Measurement Terminology The differential voltage of a differential signal can be described by two different definitions, which can cause confusion when reading data sheets or communicating with other engineers. This section addresses the measurement and description of a differential signal, so that the reader can understand and distinguish between the two different definitions. The first definition used to describe a differential signal is the absolute value of the voltage potential between the inverting and non-inverting signal. The symbol for this first measurement is typically VID or VOD, depending on if an input or output voltage is being described. The second definition used to describe a differential signal is to measure the potential of the non-inverting signal with respect to the inverting signal. The symbol for this second measurement is VSS, and is a calculated parameter. This signal does not exist in the IC with respect to ground; it only exists in reference to its differential pair. VSS can be measured directly by oscilloscopes with floating references; otherwise this value can be calculated as twice the value of VOD, as described in the first description. Figure 8 illustrates the two different definitions side-by-side for inputs, and Figure 9 illustrates the two different definitions side-by-side for outputs. The VID and VOD definitions show VA and VB DC levels that the non-inverting and inverting signals toggle between with respect to ground. VSS input and output definitions show that if the inverting signal is considered the voltage potential reference, the non-inverting signal voltage potential is now increasing and decreasing above and below the non-inverting reference. Thus, the peak-to-peak voltage of the differential signal can be measured. VID and VOD are often defined as volts (V) and VSS is often defined as volts peak-to-peak (VPP). VID Definition VSS Definition for Input Non-Inverting Clock VA 2* VID VID VB Inverting Clock VID = | VA - VB | VSS = 2* VID GND Figure 8. Two Different Definitions for Differential Input Signals VOD Definition VSS Definition for Output Non-Inverting Clock VA 2* VOD VOD VB Inverting Clock VOD = | VA - VB | VSS = 2* VOD GND Figure 9. Two Different Definitions for Differential Output Signals Refer to application note AN-912 Common Data Transmission Parameters and their Definitions (SNLA036) for more information. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 29 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9 Detailed Description 9.1 Overview The LMK0482x family are multi-purpose, jitter cleaning dual-PLL circuits, with user-programmable settings to support a flexible set of configurations for many different application requirements. PLL1 is optimized for use with an external VCXO as the PLL oscillator, while PLL2 includes a dual-range integrated VCO and distributes the VCO output to 7 integrated 10-bit channel dividers and a 13-bit SYSREF divider, yielding a total of 14 differential clock outputs at up to 8 different frequencies. The primary use case is as a dual-loop jitter cleaner (dual-loop mode), when using a reference clock with good frequency accuracy but poor phase noise to generate ultra-low jitter output clocks. Dual-loop mode also helps to maintain a high phase detector frequency and loop bandwidth in the clock generation PLL when the greatest common divisor of the reference clock frequency and the output clock frequencies is small, avoiding a low phase detector frequency that would elevate output clock phase noise. Both PLLs can optionally be disabled. By disabling PLL1, the LMK0482x can be used as a standard single-PLL clock generator with integrated VCO (single-loop mode). By disabling both PLLs, the LMK0482x can act as a distribution buffer/divider, directly connecting an input reference to the clock dividers and the SYSREF divider. The clock output dividers can also be bypassed or set to divide of 1 for distribution only mode. In a typical dual-loop configuration, the external VCXO is connected to the PLL1 N-divider, and the integrated VCO is connected to the N-divider directly. However, by routing the divided clock or SYSREF output of PLL2 to the N-divider of PLL1, PLL2, or both PLLs in a family of configurations called zero-delay mode, the LMK0482x can establish a deterministic phase relationship between reference input phase and clock output phase. Using zero-delay mode, multiple LMK0482x can be cascaded to fan out exponentially more outputs, while maintaining predictable input-to-output phase throughout the whole chain of devices. Zero-delay mode is supported in singleloop and dual-loop mode, with two dual-loop configurations: nested dual-loop (feedback connected to PLL1 Ndivider) and cascaded dual-loop (feedback connected to PLL2 N-divider). The LMK0482x may be used in JESD204B sytems by providing a device clock and SYSREF to up to 7 devices. However, alternate (non-JESD204B) systems are also possible by programming pairs of outputs to share the clock divider. Any mix of JESD204B and alternate systems can be supported. 9.1.1 Jitter Cleaning The dual-loop PLL architecture of the LMK0482x family provides the lowest jitter performance over a wide range of output frequencies and phase-noise integration bandwidths. The first-stage PLL (PLL1) is driven by an external reference clock, and uses an external VCXO or tunable crystal to provide a frequency accurate, low phase-noise reference clock for the second-stage frequency multiplication PLL (PLL2). PLL1 typically uses a narrow-loop bandwidth (10 Hz to 200 Hz) to retain the frequency accuracy of the reference clock input signal, while at the same time suppressing the higher offset frequency phase noise that the reference clock may have accumulated along its path or from other circuits. This "cleaned" reference clock provides the reference input to PLL2. The low phase-noise reference provided to PLL2 allows PLL2 to operate with a wide-loop bandwidth (typically 50 kHz to 200 kHz). The loop bandwidth for PLL2 is chosen to take advantage of the superior high-offset frequency phase-noise profile of the internal VCO, and the good low-offset frequency phase noise of the reference VCXO or tunable crystal. Ultra low jitter is achieved by allowing the external VCXO or crystal phase noise to dominate the final output phase noise at low-offset frequencies, and the internal VCO phase noise to dominate the final output phase noise at high-offset frequencies. This results in best overall phase noise and jitter performance. 9.1.2 JEDEC JESD204B Support The LMK0482x family provides support for JEDEC JESD204B. The LMK0482x clocks up to 7 JESD204B targets using 7 device clocks (DCLKoutX) and 7 SYSREF clocks (SDCLKoutY). Each device clock is grouped with a SYSREF clock. The user can reprogram SYSREF clocks to behave as extra device clocks for applications which have nonJESD204B clock requirements. 30 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Overview (continued) 9.1.3 Three PLL1 Redundant Reference Inputs The LMK0482x family has up to three reference clock inputs for PLL1. They are CLKin0, CLKin1, and CLKin2. The active clock is chosen based on CLKin_SEL_MODE. Automatic or manual switching can occur between the inputs. CLKin0, CLKin1, and CLKin2 each have their own PLL1 R dividers. CLKin0, CLKin1, and CLKin2 each support differential or single-ended inputs, and support DC coupling or AC coupling. See Driving CLKin and OSCin Inputs. CLKin1 is shared for use as an external zero-delay feedback (FBCLKin), or for use with an external VCO (Fin). CLKin2 is shared for use as OSCout. To use CLKin2 as an input, OSCout must be powered down. See VCO_MUX, OSCout_MUX, OSCout_FMT. Fast manual switching between reference clocks is possible with a external pins CLKin_SEL0 and CLKin_SEL1. For clock distribution mode, a reference signal is applied to the Fin pins for clock distribution. CLKin0 can also be used to distribute a SYSREF signal through the device. In this use case, CLKin0 may be re-clocked by Fin, or can be routed directly to the SYSREF outputs. 9.1.4 VCXO/Crystal Buffered Output CLKin2 may instead be configured as OSCout, which by default is a buffered copy of the PLL1 feedback/PLL2 reference input (OSCin). This reference input is typically a low-noise VCXO or crystal. When using a VCXO, this output can be used to clock external devices such as microcontrollers, FPGAs, and CPLDs, before the LMK0482x is programmed. The OSCout buffer output type is programmable to LVDS, LVPECL, or LVCMOS. OSCout LVPECL mode only supports 240- emitter resistors. The VCXO/crystal buffered output can be synchronized to the VCO clock distribution outputs by using cascaded zero-delay mode. The buffered output of VCXO/crystal has a deterministic phase relationship with CLKin. 9.1.5 Frequency Holdover When the reference inputs to PLL1 are lost, the LMK0482x family can enter holdover mode until a valid reference clock signal is re-established. Holdover mode forces a constant DC voltage output to the control pin of the PLL1 VCXO, ensuring minimal frequency drift while the reference inputs are absent. 9.1.6 PLL2 Integrated Loop Filter Poles The LMK0482x family features programmable 3rd- and 4th-order loop filter poles for PLL2. These internal resistors and capacitor values may be selected from a fixed range of values to achieve either a 3rd- or 4th-order loop filter response. The integrated programmable resistors and capacitors compliment external components mounted near the chip. These integrated components can be effectively disabled by programming the integrated resistors and capacitors to their minimum values. 9.1.7 Internal VCOs The LMK0482x family has two internal VCOs, selected by VCO_MUX. The output of the selected VCO is routed to the clock distribution path. This same selection is also fed back to the PLL2 phase detector through a prescaler and N-divider. 9.1.7.1 VCO1 Divider (LMK04821 only) The LMK04821 includes a VCO divider on the output of VCO1. The VCO1 divider can be programmed from 2 to 8. When using a VCO1 frequency of 2949.12 MHz and a divide of 8, frequencies as low as 11.52 MHz can be achieved. Using the VCO1_DIV limits the maximum output frequency from any output to the VCO1 frequency, divided by VCO1_DIV value. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 31 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Overview (continued) When using VCO1, the output frequency from the VCO1_DIV defines the digital delay resolution. The VCO1_DIV divider also impacts the total N divide value for PLL2 when VCO1 is selected; this should be accounted for when selecting PLL2_N and PLL2_P value. 9.1.8 External VCO Mode The Fin/Fin* input allows an external VCO to be used with PLL2 of the LMK0482x family. Using an external VCO prevents the use of CLKin1 for other purposes. 9.1.9 Clock Distribution The LMK0482x family features a total of 14 PLL2 clock outputs, driven from the internal or external VCO. All PLL2 clock outputs have programmable output types. They can be programmed to LVPECL, LVDS, or HSDS, or LCPECL. If OSCout is included in the total number of clock outputs the LMK0482x family is able to distribute, then up to 15 differential clocks. OSCout may be a buffered version of OSCin, DCLKout6, DCLKout8, or SYSREF. Its output format is programmable to LVDS, LVPECL, or LVCMOS. OSCout LVPECL mode only supports 240- emitter resistors. The following sections discuss specific features of the clock distribution channels that allow the user to control various aspects of the output clocks. 9.1.9.1 Device Clock Divider Each device clock, DCLKoutX, has a single clock output divider. The divider supports a divide range of 1 to 32 (even and odd) with 50% output duty cycle, using duty cycle correction mode. The output of this divider may also be directed to SDCLKoutY, where Y = X + 1. 9.1.9.2 SYSREF Clock Divider The SYSREF clocks, SDCLKoutY, all share a common divider. The divider supports a divide range of 8 to 8191 (even and odd). 9.1.9.3 Device Clock Delay The device clocks include both a analog and digital delay for phase adjustment of the clock outputs. The analog delay allows a nominal 25-ps step size, and range from 0 to 575 ps of total delay. Enabling the analog delay adds a nominal 500 ps of delay, in addition to the programmed value. The digital delay allows a group of outputs to be delayed from 4 to 32 VCO cycles. The delay step can be as small as half the period of the clock distribution path. For example, a 2-GHz VCO frequency results in 250 ps coarse tuning steps. The coarse (digital) delay value takes effect on the clock outputs after a SYNC event. There are two ways to use the digital delay. 1. Fixed digital delay - Allows all the outputs to have a known phase relationship upon a SYNC event. Typically performed at startup. 2. Dynamic digital delay - Allows the phase relationships of the clocks to change while the clocks continue to operate. 9.1.9.4 SYSREF Delay The global SYSREF divider includes a digital delay block, which allows a global phase shift with respect to the other clocks. Each local SYSREF clock output includes both an analog and additional local digital delay, for unique phase adjustment of each SYSREF clock. The local analog delay allows for 150-ps steps. 32 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Overview (continued) The local digital delay and SYSREF_HS bit allows the each individual SYSREF output to be delayed from, 1.5 to 11 VCO cycles. The delay step can be as small as half the period of the clock distribution path, by using the DCLKoutX_HS bit. For example, a 2-GHz VCO frequency results in 250 ps coarse tuning steps. 9.1.9.5 Glitchless Half Step and Glitchless Analog Delay The device clocks include a feature to ensure glitchless operation of the half step and analog delay operations, when enabled. 9.1.9.6 Programmable Output Formats For increased flexibility all LMK0482x family device and SYSREF clock outputs, DCLKoutX and SDCLKoutY, can be programmed to an LVDS, HSDS, LVPECL, or LCPECL output type. The OSCout can be programmed to an LVDS, LVPECL, or LVCMOS output type. OSCout LVPECL mode only supports 240- emitter resistors. Any LVPECL output type can be programmed to 1600- or 2000-mVpp amplitude levels. The 2000-mVpp LVPECL output type is a Texas Instruments proprietary configuration that produces a 2000-mVpp differential swing for compatibility with many data converters, and is known as 2VPECL. LCPECL allows for DC coupling SYSREF to low-voltage converters. 9.1.9.7 Clock Output Synchronization Using the SYNC input causes all active clock outputs to share a rising edge, as programmed by fixed digital delay. The SYNC event must occur for digital delay values to take effect. 9.1.10 Zero-Delay The LMK0482x family supports two types of zero-delay. 1. Cascaded zero-delay 2. Nested zero-delay Cascaded zero-delay mode establishes a fixed deterministic phase relationship of the phase of the PLL2 input clock (OSCin) to the phase of a clock selected by the feedback mux. The zero-delay feedback may performed with an internal feedback from CLKout6, CLKout8, SYSREF, or with an external feedback loop into the FBCLKin port as selected by the FB_MUX. Because OSCin has a fixed deterministic phase relationship to the feedback clock, OSCout will also have a fixed deterministic phase relationship to the feedback clock. In this mode, the PLL1 input clock (CLKinX) also has a fixed deterministic phase relationship to PLL2 input clock (OSCin); this results in a fixed deterministic phase relationship between all clocks from CLKinX to the clock outputs. Nested zero-delay mode establishes a fixed deterministic phase relationship of the phase of the PLL1 input clock (CLKinX) to the phase of a clock selected by the feedback mux. The zero-delay feedback may performed with an internal feedback from CLKout6, CLKout8, SYSREF, or with an external feedback loop into the FBCLKin port as selected by the FB_MUX. Without using zero-delay mode, there are numerous possible fixed phase relationships from clock input to clock output, depending on the clock output divide value. Careful selection of the zero-delay feedback value can reduce the number of fixed phase relationships from clock input to clock output, potentially to as few as one. As a result, zero-delay simplifies input-to-output phase guarantees, especially across multiple devices. For more information, see the application note Multi-Clock Synchronization. Using an external zero-delay feedback prevents the use of CLKin1 for other purposes. 9.1.11 Status Pins The LMK0482x provides status pins, which can be monitored for feedback, or in some cases used for input depending upon device programming. For example: * The CLKin_SEL0 pin may be configured as an output, indicating the LOS (loss-of-signal) for CLKin0. * The CLKin_SEL1 pin may be configured as an input, for selecting the active clock input. * The Status_LD1 pin may indicate if the device is locked (PLL1 and PLL2 locked). Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 33 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Overview (continued) * The Status_LD2 pin may indicate if PLL2 is locked. The status pins can be programmed to a variety of other outputs, including PLL divider outputs, combined PLL lock detect signals, PLL1 Vtune railing, SPI readback, and so forth. Refer to the programming section of this data sheet for more information. 34 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.2 Functional Block Diagram Figure 10 and Figure 11 illustrate the complete LMK0482x family block diagram. Figure 10. Detailed LMK04821 Block Diagram Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 35 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Functional Block Diagram (continued) Figure 11. Detailed LMK04826 and LMK04828 Block Diagram 36 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Functional Block Diagram (continued) CLKoutX_Y_PD DCLKout6/8 to FB_MUX DCLKoutX_ADLY_PD VCO DDLY (4 to 32) DCLKoutX_HSg_PD Divider (1 to 32) DCLKoutX_ADLYg_PD HS/ DCC DCLKout0, 2, 4, 6, 8, 10, 12 DCLKoutX _POL DCLKoutX_DDLY_PD DCLKoutX _MUX DCLKoutX _ADLY _MUX DDDLYdX_EN DCLKoutX_ FMT Analog DLY CLKoutX_Y_ODL CLKoutX_Y_IDL SYNC_ 1SHOT_EN SYSREF_GBL_PD SDCLKoutY_DIS_MODE One Shot SDCLKoutY _POL SYNC_ DISX SDCLKoutY_PD SYSREF/SYNC Legend SPI Register Digital DLY SYSREF/SYNC Clock VCO/Distribution Clock Half Step Analog DLY SDCLKoutY _MUX SDCLKoutY _ADLY_EN SDCLKoutY_ FMT SDCLKout1, 3, 5, 7, 9, 11, 13 SYSREF_CLR Figure 12. Device and SYSREF Clock Output Block Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 37 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Functional Block Diagram (continued) Figure 13. SYNC/SYSREF Clocking Paths 38 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.3 Feature Description 9.3.1 SYNC/SYSREF To properly use SYNC or SYSREF for JESD204B, it is important to understand the SYNC/SYSREF system. The SYNC and SYSREF signals share the same clocking path, with SYNC_DISX bits used to enable the path from SYSREF/SYNC to each divider reset port. Figure 12 illustrates the detailed diagram of a clock output block with SYNC circuitry included.Figure 13 illustrates the interconnects and highlights some important registers used in controlling the device for SYNC/SYSREF purposes. To reset or synchronize a divider, the following conditions must be met: 1. SYNC_EN must be set. This ensures proper operation of the SYNC circuitry. 2. SYSREF_MUX and SYNC_MODE must be set to a proper combination to provide a valid SYNC/SYSREF signal. - If SYSREF block is being used, the SYSREF_PD bit must be clear. - If the SYSREF Pulser is being used, the SYSREF_PLSR_PD bit must be clear. - For each SDCLKoutY being used for SYSREF, respective SDCLKoutY_PD bits must be cleared. 3. SYSREF_DDLY_PD and DCLKoutX_DDLY_PD bits must be clear to power up the digital delay circuitry during SYNC. After the SYNC event, these bits may be set to reduce power consumption. 4. The SYNC_DISX bit must be clear to allow the SYNC/SYSREF signal to reset the divider circuit. The SYSREF_MUX register selects the SYNC source. 5. Other bits which impact the operation of SYNC, such as SYNC_1SHOT_EN, may be set as desired. Table 1 illustrates the some possible combinations of SYSREF_MUX and SYNC_MODE. Table 1. Some Possible SYNC Configurations NAME SYNC disabled SYNC_MODE SYSREF_MUX 0 0 OTHER DESCRIPTION CLKin0_OUT_MUX 0 No SYNC occurs. Pin or SPI SYNC 1 0 CLKin0_OUT_MUX 0 Basic SYNC functionality, SYNC pin polarity is selected by SYNC_POL. To achieve SYNC through SPI, toggle the SYNC_POL bit. Differential input SYNC 0 or 1 0 or 1 CLKin0_OUT_MUX = 0 Differential CLKin0 now operates as SYNC input. JESD204B pulser on pin transition. 2 2 SYSREF_PULSE_CNT sets pulse count Produce SYSREF_PULSE_CNT programmed number of pulses on pin transition. SYNC_POL can be used to cause SYNC through SPI. JESD204B pulser on SPI programming. 3 2 SYSREF_PULSE_CNT sets pulse count Programming the SYSREF_PULSE_CNT register starts sending the number of pulses. Re-clocked SYNC 1 1 SYSREF operational, SYSREF divider as required for training frame size. Allows precise SYNC for n-bit frame training patterns for non-JESD converters such as LM97600. External SYSREF request 0 2 SYSREF_REQ_EN = 1 Pulser powered up When the SYNC pin is asserted, continuous SYSERF pulses occur. Turning on and off of the pulses is synchronized, to prevent runt pulses from occurring on SYSREF. Continuous SYSREF X 3 (1) SYSREF_PD = 0 SYSREF_DDLY_PD = 0 SYSREF_PLSR_PD = 1 (1) Continuous SYSREF signal. Useful for validating phase alignment of SYSREF clocks, but not recommended for use in low-noise applications due to crosstalk spurs. SDCLKoutY_PD = 0 as required per SYSREF output. This applies to any SYNC or SYSREF output on SDCLKoutY when SDCLKoutY_MUX = 1 (SYSREF output) Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 39 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Feature Description (continued) Table 1. Some Possible SYNC Configurations (continued) NAME SYNC_MODE Direct SYSREF distribution SYSREF_MUX 0 0 OTHER DESCRIPTION CLKin0_OUT_MUX = 0 SDCLKoutY_DDLY = 0 (Local sysref DDLY bypassed) SYSREF_DDLY_PD = 1 SYSREF_PLSR_PD = 1 SYSREF_PD = 1. A direct fan-out of SYSREF with no re-clocking to clock distribution path. 9.3.2 JEDEC JESD204B 9.3.2.1 How To Enable SYSREF Table 2 summarizes the bits needed to make SYSREF functionality operational. Table 2. SYSREF Bits REGIS TER FIELD VALUE DESCRIPTION 0x140 SYSREF_PD 0 Must be clear to power-up SYSREF circuitry. 0x140 SYSREF_DDLY_ PD 0 Must be clear to power-up digital delay circuitry during initial SYNC, to ensure deterministic timing. 0x143 SYNC_EN 1 Must be set to enable SYNC. 0x143 SYSREF_CLR 10 Do not hold local SYSREF_DDLY block in reset except at start. Anytime SYSREF_PD = 1 because of user programming or device RESET, it is necessary to set SYSREF_CLR for 15 clock distribution path cycles to clear the local SYSREF digital delay. After clearing local delays, SYSREF_CLR must be cleared to allow SYSREF to operate. Enabling JESD204B operation involves synchronizing all the clock dividers with the SYSREF divider, then configuring the actual SYSREF functionality. 9.3.2.1.1 Setup of SYSREF Example The following procedure is a programming example for a system operating with a 3000-MHz VCO frequency. Use DCLKout0 and DCLKout2 to drive converters at 1500 MHz. Use DCLKout4 to drive an FPGA at 150 MHz. Synchronize the converters and FPGA using two SYSREF pulses at 10 MHz. 1. Program registers 0x000 to 0x1fff as desired. Key to prepare for SYSREF operations (see Recommended Programming Sequence): a. Prepare for manual SYNC: SYNC_POL = 0, SYNC_MODE = 1, SYSREF_MUX = 0 b. Setup output dividers as per example: DCLKout0_DIV and DCLKout2_DIV = 2 for frequency of 1500 MHz. DCLKout4_DIV = 20 for frequency of 150 MHz. c. Setup output dividers as per example: SYSREF_DIV = 300 for 10 MHz SYSREF d. Setup SYSREF: SYSREF_PD = 0, SYSREF_DDLY_PD = 0, DCLKout0_DDLY_PD = 0, DCLKout2_DDLY_PD = 0, DCLKout4_DDLY_PD = 0, SYNC_EN = 1, SYSREF_PLSR_PD = 0, SYSREF_PULSE_CNT = 1 (2 pulses). SDCLKout1_PD = 0, SDCLKout3_PD = 0 e. Clear Local SYSREF DDLY: SYSREF_CLR = 1. 2. Establish deterministic phase relationships between SYSREF and the device clock for JESD204B: a. Set device clock and SYSREF divider digital delays: DCLKout0_DDLY_CNTH, DCLKout0_DDLY_CNTL, DCLKout2_DDLY_CNTH, DCLKout2_DDLY_CNTL, DCLKout4_DDLY_CNTH, DCLKout4_DDLY_CNTL, SYSREF_DDLY. b. Set device clock digital delay half steps: DCLKout0_HS, DCLKout2_HS, DCLKout4_HS. c. Set SYSREF clock digital delay as required to achieve known phase relationships: SDCLKout1_DDLY, SDCLKout3_DDLY, SDCLKout5_DDLY. d. To allow SYNC to effect dividers: SYNC_DIS0 = 0, SYNC_DIS2 = 0, SYNC_DIS4 = 0, SYNC_DISSYSREF = 0 40 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com 3. 4. 5. 6. SNAS605AS - MARCH 2013 - REVISED MAY 2020 e. Perform SYNC by toggling SYNC_POL = 1, then SYNC_POL = 0. When the dividers are synchronized, disable SYNC from resetting these dividers. It is not desired for SYSREF to reset it's own divider or the dividers of the output clocks. a. Prevent SYSREF from affecting dividers: SYNC_DIS0 = 1, SYNC_DIS2 = 1, SYNC_DIS4 = 1, SYNC_DISSYSREF = 1. Release reset of local SYSREF digital delay. a. SYSREF_CLR = 0. Note this bit needs to be set for only 15 clock distribution path cycles after SYSREF_PD = 0. Set SYSREF operation. a. Allow pin SYNC event to start pulser: SYNC_MODE = 2. b. Select pulser as SYSREF signal: SYSREF_MUX = 2. After the procedure is complete, asserting the SYNC pin or toggling SYNC_POL results in a series of 2 SYSREF pulses. 9.3.2.1.2 SYSREF_CLR The local digital delay of the SDCLKout is implemented as a shift buffer. To ensure no unwanted pulses occur at this SYSREF output at startup when using SYSREF, clear the buffers by setting SYSREF_CLR = 1 for 15 VCO clock cycles. This bit is set after a reset; thus, it must be cleared before the SYSREF output is used. 9.3.2.2 SYSREF Modes 9.3.2.2.1 SYSREF Pulser This mode allows for the output of 1, 2, 4, or 8 SYSREF pulses for every SYNC pin event or SPI programming. This implements the gapped periodic functionality of the JEDEC JESD204B specification. When in SYSREF pulser mode, programming the field SYSREF_PULSE_CNT in register 0x13E results in the pulser sending the programmed number of pulses. 9.3.2.2.2 Continuous SYSREF This mode allows for continuous output of the SYSREF clock. Continuous operation of SYSREF is not recommended, due to crosstalk from the SYSREF clock to device clock. JESD204B is designed to operate with a single burst of pulses to initialize the system at startup, after which it is theoretically not required to send another SYSREF, because the system continues to operate with deterministic phases. If continuous operation of SYSREF is required, consider using a SYSREF output from a non-adjacent output or SYSREF from the OSCout pin, to minimize crosstalk. 9.3.2.2.3 SYSREF Request This mode allows an external source to synchronously turn on or off a continuous stream of SYSREF pulses, using the SYNC/SYSREF_REQ pin. Set up the mode by programming SYSREF_REQ_EN = 1 and SYSREF_MUX = 2 (Pulser). The pulser does not need to be powered for this mode of operation. When the SYSREF_REQ pin is asserted, the SYSREF_MUX is synchronously set to continuous mode, providing continuous pulses at the SYSREF frequency, until the SYSREF_REQ pin is unasserted and the final SYSREF pulse completes sending synchronously. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 41 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.3.3 Digital Delay Digital (coarse) delay allows a group of outputs to be delayed by 4 to 32 VCO cycles. The delay step can be as small as half the period of the VCO cycle, by using the DCLKoutX_HS bit. There are two ways to use the digital delay: 1. Fixed digital delay 2. Dynamic digital delay In both delay modes, the regular clock divider is substituted with an alternative divide value. The substitute divide value consists of two values, DCLKoutX_DDLY_CNTH and DCLKoutX_DDLY_CNTL. The minimum _CNTH/_CNTL value is 2 and the maximum _CNTH/_CNTL value is 16. This results in a minimum alternative divide value of 4 and a maximum of 32. 9.3.3.1 Fixed Digital Delay Fixed digital delay value takes effect on the clock outputs after a SYNC event. As such, the outputs are LOW for a while during the SYNC event. Applications that cannot accept clock interruption when adjusting digital delay should use dynamic digital delay. 9.3.3.1.1 Fixed Digital Delay Example Assuming the device already has the following initial configurations, and the application should delay DCLKout2 by one VCO cycle compared to DCLKout0: * VCO frequency = 2949.12 MHz * DCLKout0 = 368.64 MHz (DCLKout0_DIV = 8) * DCLKout2 = 368.64 MHz (DCLKout2_DIV = 8) These steps should be followed: 1. Set DCLKout0_DDLY_CNTH = 4 and DCLKout2_DDLY_CNTH = 4. First part of delay for each clock. 2. Set DCLKout0_DDLY_CNTL = 4 and DCLKout2_DDLY_CNTL = 5. Second part of delay for each clock. 3. Set DCLKout0_DDLY_PD = 0 and DCLKout2_DDLY_PD = 0. Power up the digital delay circuit. 4. Set SYNC_DIS0 = 0 and SYNC_DIS2 = 0. Allow the output to be synchronized. 5. Perform SYNC by asserting, then deasserting SYNC. Either by using SYNC_POL bit or the SYNC pin. 6. When the SYNC is complete, power down DCLKout0_DDLY_PD = 1 and/or DCLKout2_DDLY_PD = 1 to save power. 7. Set SYNC_DIS0 = 1 and SYNC_DIS2 = 1, to prevent the outputs from being synchronized by other SYNC/SYSREF events. DCLKout0 368.64 MHz No CLKout during SYNC DCLKout2 368.64 MHz SYNC event 1 VCO cycle delay Figure 14. Fixed Digital Delay Example 42 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.3.3.2 Dynamic Digital Delay Dynamic digital delay allows the phase of clocks to be changed with respect to each other, with little impact to the clock signal. This is accomplished by substituting the regular clock divider with an alternate divide value for one cycle. This substitution occurs a number of times equal to the value programmed into the DDLYd_STEP_CNT field for all outputs with DDLYdX_EN = 1. * By programming a larger alternate divider (delay) value, the phase of the adjusted outputs is delayed with respect to the other clocks. * By programming a smaller alternate divider (delay) value, the phase of the adjusted output is advanced with respect to the other clocks. Table 3 shows the recommended DCLKoutX_DDLY_CNTH and DCLKoutX_DDLY_CNTL alternate divide setting for delay by one VCO cycle. The clock output is high during the DCLKoutX_DDLY_CNTH time to permit a continuous output clock. The clock output is low during the DCLKoutX_DDLY_CNTL time. Table 3. Recommended DCLKoutX_DDLY_CNTH/_CNTL Values for Delay by One VCO Cycle CLOCK DIVIDER _CNTH _CNTL CLOCK DIVIDER _CNTH 2 2 3 17 9 9 3 3 4 18 9 10 4 2 3 19 10 10 5 3 3 20 10 11 6 3 4 21 11 11 7 4 4 22 11 12 8 4 5 23 12 12 9 5 5 24 12 13 10 5 6 25 13 13 11 6 6 26 13 14 12 6 7 27 14 14 13 7 7 28 14 15 14 7 8 29 15 15 15 8 8 30 15 0 (1) 16 8 9 31 0 (1) 0 (1) (1) _CNTL To achieve _CNTH/_CNTL value of 16, 0 must be programmed into the _CNTH/_CNTL field. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 43 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.3.3.3 Single and Multiple Dynamic Digital Delay Example In this example, two separate adjustments are made to the device clocks. In the first adjustment, a single delay of 1 VCO cycle occurs between DCLKout2 and DCLKout0. In the second adjustment, two delays of 1 VCO cycle occur between DCLKout2 and DCLKout0. At this point in the example, DCLKout2 is delayed 3 VCO cycles behind DCLKout0. Assuming the device already has the following initial configurations: * VCO frequency: 2949.12 MHz * DCLKout0 = 368.64 MHz, DCLKout0_DIV = 8 * DCLKout2 = 368.64 MHz, DCLKout2_DIV = 8 The following steps illustrate the example above: 1. Set DCLKout2_DDLY_CNTH = 4. First part of delay for DCLKout2. 2. Set DCLKout2_DDLY_CNTL = 5. Second part of delay for DCLKout2. 3. Set DCLKout2_DDLY_PD = 0. Enable the digital delay for DCLKout2. 4. Set DDLYd2_EN = 1. Enable dynamic digital delay for DCLKout2. 5. Set SYNC_DIS0 = 1 and SYNC_DIS2 = 0. Sync should be disabled to DCLKout0, but not DCLKout2. 6. Set SYNC_MODE = 3. Enable SYNC event from SPI write to the DDLYd_STEP_CNT register. 7. Set SYNC_MODE = 2, SYSREF_MUX = 2. Setup proper SYNC settings. 8. Set DDLYd_STEP_CNT = 1. This begins the first adjustment. Before step 8 DCLKout2 clock edge is aligned with DCLKout0. After step 8, DCLKout2 counts four VCO cycles high and then five VCO cycles low as programmed by DCLKout2_DDLY_CNTH and DCLKout2_DDLY_CNTL fields, effectively delaying DCLKout2 by one VCO cycle with respect to DCLKout0. This is the first adjustment. 9. Set DDLYd_STEP_CNT = 2. This begins the second adjustment. Before step 9, DCLKout2 clock edge was delayed 1 VCO cycle from DCLKout0. After step 9, DCLKout2 counts four VCO cycles high and then five VCO cycles low, as programmed by DCLKout2_DDLY_CNTH and DCLKout2_DDLY_CNTL fields twice, delaying DCLKout2 by two VCO cycles with respect to DCLKout0. This is the second adjustment. VCO 2949.12 MHz DCLKout0 368.64 MHz DCLKout2 368.64 MHz First Adjustment CNTH = 4 CNTL = 5 DCLKout2 368.64 MHz Second Adjustment CNTH = 4 CNTL = 5 CNTH = 4 CNTL = 5 Figure 15. Single and Multiple Adjustment Dynamic Digital Delay Example 44 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.3.4 SYSREF to Device Clock Alignment To ensure proper JESD204B operation, the timing relationship between the SYSREF and the device clock must be adjusted for optimum setup and hold time as shown in Added timing alignment figure, alignment equations to SYSREF to Device Clock Alignment . The global SYSREF digital delay (SYSREF_DDLY). local SYSREF digital delay (SDCLKoutY_DDLY), local SYSREF half step (SDCLKoutY_HS), and local SYSREF analog delay (SDCLKoutY_ADLY, SDCLKoutY_ADLY_EN) can be adjusted to provide the required setup and hold time between SYSREF and device clock. It is also possible to adjust the device clock digital delay (DCLKoutX_DDLY_CNTH, DCLKoutX_DDLY_CNTL), device clock half step (DCLKoutX_HS), device clock analog delay (DCLKoutX_ADLY, DCLKoutX_ADLY_EN), and device clock muxes (DCLKoutX_MUX, DCLKoutX_ADLY_MUX) to adjust phase with respect to SYSREF. Figure 16. SYSREF to Device Clock Timing Alignment Depending on the settings for DCLKoutX and the SYSREF divider, some adjustment may be needed to correctly align DCLKoutX to SDCLKoutY. Equation 1 and Equation 2 predict the relative DCLKoutX to SDCLKoutY delay: DELAYDCLK = DCLKoutX_DDLY_CNTH + DCLKoutX_DDLY_CNTL DELAYSDCLK = SYSREF_DDLY + SDCLKoutY_DDLY + SYSREF_DIV_ADJUST + DCLKout_MUX_ADJUST (1) where * * SYSREF_DIV_ADJUST = 2 IF (SYSREF_DIV % 4 < 2) ELSE 3 DCLKoutX_MUX_ADJUST = 1 IF (Duty Cycle Correction enabled) ELSE 0 (2) For the relative delay equations, the cycle delay rather than the register value should be used, since cycle delay does not always equal register value (example: _CNTH/_CNTL=0, delay=16). Device clock duty cycle correction can be enabled for both digital and analog paths, either by setting DCLKoutX_MUX=1 (digital only), or by setting DCLKoutX_MUX=3 and DCLKoutX_ADLY_MUX=1. If half step is enabled on either path, delay can be included by subtracting 0.5 from the enabled path. As an example, if DCLKoutX_DDLY_CNTH=7, DCLKoutX_DDLY_CNTL=6, SYSREF_DDLY=8, SDCLKoutY_DDLY=2 cycles, SYSREF_DIV=30, DCLKoutX_MUX=1, DCLKoutX_HS=0, SDCLKoutX_HS=0: * DELAYDCLK = 7 + 6 = 13 * SYSREF_DIV_ADJUST = (30 % 4 < 2) ? 2 : 3 = 3 * DCLKoutX_MUX_ADJUST = DCC ? 1 : 0 = 0 * DELAYSDCLK = 8 + 2 + 3 + 0 = 13 To calculate the expected time delay from the first edge of DCLKoutX to the first edge of SDCLKoutY, refer to Equation 3. Substitute the analog delays with the appropriate time values (in seconds) according to DCLKoutX_ADLY, DCLKoutX_ADLY_MUX, DCLKout_MUX and SDCLKoutY_ADLY_EN, SDCLKoutY_ADLY. tsJESD204B is provided in the Electrical Characteristics section for the conditions in the example above as -80 ps. tDCLK-to-SDCLK = (FDistribution)-1 x (DELAYSDCLK - DELAYDCLK) + SDCLKoutY_ADLY - DCLKoutY_ADLY + tsJESD204B Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback (3) 45 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.3.5 Input Clock Switching Manual, pin select, and automatic are three kinds clock input switching modes that can be set with the CLKin_SEL_MODE register. The following sections describe how the active input clock is selected and what causes a switching event in the various clock input selection modes. 9.3.5.1 Input Clock Switching - Manual Mode When CLKin_SEL_MODE is 0, 1, or 2, then CLKin0, CLKin1, or CLKin2 respectively is always selected as the active input clock. Manual mode also overrides the EN_CLKinX bits, such that the CLKinX buffer operates even if EN_CLKinX = 0. If holdover is entered in this mode, the device re-locks to the selected CLKin upon holdover exit. 9.3.5.2 Input Clock Switching - Pin Select Mode When CLKin_SEL_MODE is 3, the pins CLKin_SEL0 and CLKin_SEL1 select which clock input is active. Configuring Pin Select Mode The CLKin_SEL0_TYPE must be programmed to an input value for the CLKin_SEL0 pin to function as an input for pin select mode. The CLKin_SEL1_TYPE must be programmed to an input value for the CLKin_SEL1 pin to function as an input for pin select mode. If the CLKin_SELX_TYPE is set as output, the pin input value is considered low. The polarity of CLKin_SEL0 and CLKin_SEL1 input pins can be inverted with the CLKin_SEL_INV bit. Table 4 defines which input clock is active depending on CLKin_SEL0 and CLKin_SEL1 state. Table 4. Active Clock Input - Pin Select Mode, CLKin_SEL_INV = 0 PIN CLKin_SEL1 PIN CLKin_SEL0 ACTIVE CLOCK Low Low CLKin0 Low High CLKin1 High Low CLKin2 High High Holdover The pin select mode ignores the EN_CLKinX bits, such that the CLKinX buffer operates even if EN_CLKinX = 0. To switch as fast as possible, keep the switchable clock input buffers enabled (EN_CLKinX = 1). 46 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.3.5.3 Input Clock Switching - Automatic Mode When CLKin_SEL_MODE is 4 and LOS_EN = 1, the active clock is selected in round-robin order of enabled clock inputs, starting on an input clock switch event. The switching order of the clocks is CLKin0 CLKin1 CLKin2 CLKin0, and so forth. For a clock input to be eligible to be switched through, it must be enabled using EN_CLKinX. The LOS_TIMEOUT should also be set to a frequency below the input frequency. To ensure LOS is valid for AC-coupled inputs, the MOS mode must be set for CLKinX and no termination is allowed to be between the pins unless DC-blocked. For example, with an LVDS differential signal into CLKin0, no 100- termination should be placed directly across CLKin0 and CLKin0* pins on the IC side of the AC coupling capacitors. 100 could instead be placed on the transmitter side of the AC coupling capacitors. Starting Active Clock When programming this mode, the currently active clock remains active if PLL1 lock detect is high. To ensure a particular clock input is the active clock when starting this mode, program CLKin_SEL_MODE to the manual mode which selects the desired clock input (CLKin0, 1, or 2). Wait for PLL1 to lock PLL1_DLD = 1, then select this mode with CLKin_SEL_MODE = 4. 9.3.6 Digital Lock Detect Both PLL1 and PLL2 support digital lock detect. Digital lock detect compares the phase between the reference path (R) and the feedback path (N) of the PLL at the phase detector. When the time error(phase error) between the two signals is less than a specified window size (), a lock detect count increments. When the lock detect count reaches a user-specified value, PLL1_DLD_CNT or PLL2_DLD_CNT, lock detect is asserted (true). When digital lock detect is true, a single phase comparison outside the specified window causes digital lock detect to be deasserted (false). This is illustrated in Figure 17 . NO START PLLX Lock Detected = False Lock Count = 0 NO YES Phase Error < g Increment PLLX Lock Count PLLX Lock Count = PLLX_DLD_CNT YES PLLX Lock Detected = True Phase Error < g YES NO Figure 17. Digital Lock Detect Flowchart This incremental lock detect count feature functions as a digital filter, to ensure that lock detect is not asserted when the phases of R and N are within the specified tolerance for a brief time during initial phase lock. See Digital Lock Detect Frequency Accuracy for more detailed information on programming the registers to achieve a specified frequency accuracy in ppm with lock detect. The digital lock detect signal can be monitored on the Status_LD1 or Status_LD2 pin. The pin may be programmed to output the status of lock detect for PLL1, PLL2, or both PLL1 and PLL2. The digital lock detect feature can also be used with holdover to automatically exit holdover mode. See Exiting Holdover for more info. NOTE In cases where the period of the phase detector frequency approaches the value of the default PLL1_WND_SIZE increment (40 ns), the lock detect circuit will not function with the default value of PLL1_WND_SIZE. For PLL1 phase detector frequencies at or above 25 MHz, TI recommends setting PLL1_WND_SIZE less than or equal to 0x02 (19 ns). Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 47 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.3.7 Holdover Holdover mode causes PLL2 to stay locked on frequency with minimal frequency drift when an input clock reference to PLL1 becomes invalid, when PLL1 loses lock, or when the CPout1 voltage is outside of a userspecified acceptable range. While in holdover mode, the PLL1 charge pump is TRI-STATED and a fixed tuning voltage is set on CPout1 to operate PLL1 in open loop. 9.3.7.1 Enable Holdover Program HOLDOVER_EN = 1 to enable holdover mode. Enabling holdover mode does not place the device in holdover unless the relevant criteria have been met (example: PLL1 loss of lock). Program HOLDOVER_FORCE = 1 to force the device into holdover. Holdover mode can be configured to set the CPout1 voltage upon holdover entry, to a fixed user-defined voltage or a tracked voltage. 9.3.7.1.1 Fixed (Manual) CPout1 Holdover Mode By programming MAN_DAC_EN = 1, the MAN_DAC value is set on the CPout1 pin during holdover. The user can optionally enable CPout1 voltage tracking (TRACK_EN = 1), read back the tracked DAC value, then reprogram MAN_DAC value to a user-desired value based on information from previous DAC read backs. This allows the most user control over the holdover CPout1 voltage, but also requires more user intervention. 9.3.7.1.2 Tracked CPout1 Holdover Mode By programming MAN_DAC_EN = 0 and TRACK_EN = 1, the tracked voltage of CPout1 is set on the CPout1 pin during holdover. When the DAC has acquired the current CPout1 voltage, the DAC_Locked signal is set, which may be observed on Status_LD1 or Status_LD2 pins by programming PLL1_LD_MUX or PLL2_LD_MUX, respectively. Updates to the DAC value for the Tracked CPout1 sub-mode occurs at the rate of the PLL1 phase detector frequency divided by (DAC_CLK_MULT x DAC_CLK_CNTR). The DAC update rate should be programmed for 100 kHz to ensure DAC holdover accuracy. The ability to program slow DAC update rates, for example one DAC update per 4.08 seconds when using 1024kHz PLL1 phase-detector frequency with DAC_CLK_MULT = 16,384 and DAC_CLK_CNTR = 255, allows the device to look-back and set CPout1 at previous "good" CPout1 tuning voltage values before the event which caused holdover to occur. The current voltage of DAC value can be read back using RB_DAC_VALUE; see RB_DAC_VALUE. 9.3.7.2 Entering Holdover There are several ways to enter holdover. * HOLDOVER_LOS_DET = 1 and a loss of active reference is detected. * HOLDOVER_PLL1_DET = 1 and PLL1 loss of lock is detected. * HOLDOVER_VTUNE_DET = 1 and the voltage monitored by the DAC on CPout1 is less than the value set by DAC_TRIP_LOW, or greater than the value set by DAC_TRIP_HIGH. * HOLDOVER_FORCE = 1. 9.3.7.3 During Holdover PLL1 is run in open-loop mode. * PLL1 charge pump is set to TRI-STATE. * PLL1 DLD is deasserted. * The HOLDOVER status is asserted. * During holdover, if PLL2 was locked prior to entry of holdover mode, PLL2 DLD continues to be asserted. * CPout1 voltage is set to: - a voltage set in the MAN_DAC register (MAN_DAC_EN = 1). - a voltage determined to be the last valid CPout1 voltage (MAN_DAC_EN = 0). * PLL1 attempts to lock with the active clock input. 48 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 The HOLDOVER status signal can be monitored on the Status_LD1 or Status_LD2 pin by programming the PLL1_DLD_MUX or PLL2_DLD_MUX register to Holdover Status. 9.3.7.4 Exiting Holdover Holdover mode can be exited in one of two ways. * Manually, by programming the device from the host. * Automatically, by a clock operating within a specified ppm of the current PLL1 frequency on the active clock input. 9.3.7.5 Holdover Frequency Accuracy and DAC Performance When in holdover mode, PLL1 runs in open loop and the DAC sets the CPout1 voltage. If fixed CPout1 mode is used, then the output of the DAC is voltage-dependant upon the MAN_DAC register. If tracked CPout1 mode is used, then the output of the DAC is the voltage at the CPout1 pin before holdover mode was entered. When using tracked mode and MAN_DAC_EN = 1, during holdover the DAC value is loaded with the programmed value in MAN_DAC, not the tracked value. When in tracked CPout1 mode, the DAC has a worst-case tracking error of 2 LSBs when PLL1 tuning voltage is acquired. The step size is approximately 3.2 mV, thus the VCXO frequency error during holdover mode caused by the DAC tracking accuracy is 6.4 mV x Kv, where Kv is the tuning sensitivity of the VCXO in use. Thus, the accuracy of the system when in holdover mode in ppm is: Holdover accuracy (ppm) = 6.4 mV x Kv x 1e6 VCXO Frequency (4) Example: consider a system with a 19.2-MHz clock input, and a 153.6-MHz VCXO with a Kv of 17 kHz/V. The accuracy of the system in holdover in ppm is: 0.71 ppm = 6.4 mV x 17 kHz/V x 1e6 / 153.6 MHz (5) It is important to account for this frequency error when determining the allowable frequency error window to cause holdover mode to exit. 9.3.7.6 Holdover Mode - Automatic Exit of Holdover The LMK0482x device can be programmed to automatically exit holdover mode when the frequency on the active clock input achieves a specified accuracy. The programmable variables include PLL1_WND_SIZE and HOLDOVER_DLD_CNT. See Digital Lock Detect Frequency Accuracy to calculate the register values to cause holdover to automatically exit upon reference signal recovery to within a user specified ppm error of the holdover frequency. The time to exit holdover may vary, because the condition for automatic holdover exit is for the reference and feedback signals to have a time/phase error less than a programmable value. Because two clock signals may be very close in frequency but not close in phase, it may take a long time for the phases of the clocks to align themselves within the allowable time/phase error before holdover exits. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 49 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.4 Device Functional Modes The following section describes the settings to enable various modes of operation for the LMK0482x family. See Figure 12 and Figure 13 for visual diagrams of each mode. The LMK0482x family is a flexible device that can be configured for many different use cases. The following simplified block diagrams show the user the different use cases of the device. 9.4.1 Dual PLL Figure 18 illustrates the typical use case of the LMK0482x family in dual-loop mode. In dual-loop mode, the reference to PLL1 is from CLKin0, CLKin1, or CLKin2. An external VCXO or tunable crystal is used to provide feedback for the first PLL, and a reference to the second PLL. This first PLL cleans the jitter with the VCXO or low-cost tunable crystal by using a narrow loop bandwidth. The VCXO or tunable crystal output may be buffered through the OSCout port. The VCXO or tunable crystal is used as the reference to PLL2, and may be doubled using the frequency doubler. The internal VCO drives up to seven divide/delay blocks, which drive up to 14 clock outputs. Hitless switching and holdover functionality are optionally available when the input reference clock is lost. Holdover works by fixing the tuning voltage of PLL1 to the VCXO or tunable crystal. It is also possible to use an external VCO in place of the PLL2 internal VCO. In this case, one less CLKin is available as a reference. LMK04821 includes VCO1 divider on VCO1 output. PLL1 PLL2 R N Phase Detector PLL1 External VCXO or Tunable Crystal External Loop Filter External Loop Filter OSCout OSCout* OSCin CLKinX CLKinX* Up to 3 inputs CPout1 Up to 1 OSCout 7 blocks CPout2 R Input Buffer N Phase Detector PLL2 Device Clock Divider Digital Delay Analog Delay Partially Integrated Loop Filter Dual Internal VCOs LMK0482x SYSREF Digital Delay Analog Delay 7 Device Clocks DCLKoutX DCLKoutX* 7 SYSREF or Device Clocks SDCLKoutY SDCLKoutY* 1 Global SYSREF Divider Figure 18. Simplified Functional Block Diagram for Dual-Loop Mode Table 5. Dual-Loop Mode Register Configuration 50 FIELD REGISTER ADDRESS FUNCTION VALUE PLL1_NCLK_MUX 0x13F Selects the input to the PLL1 N divider 0 OSCin PLL2_NCLK_MUX 0x13F Selects the input to the PLL2 N divider 0 PLL2_P FB_MUX_EN 0x13F Enables the feedback mux 0 Disabled FB_MUX 0x13F Selects the output of the feedback mux X Don't care because FB_MUX is disabled OSCin_PD 0x140 Powers down the OSCin port 0 Powered up CLKin0_OUT_MUX 0x147 Selects where the output of CLKin0 is directed. 2 PLL1 CLKin1_OUT_MUX 0x147 Selects where the output of CLKin1 is directed. 2 PLL1 VCO_MUX 0x138 Selects the VCO 0, 1 or an external VCO 0 or 1 VCO 0 or VCO 1 Submit Documentation Feedback SELECTED VALUE Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.4.2 Zero-Delay Dual PLL Figure 19 illustrates the use case of cascaded zero-delay dual-loop mode. This configuration differs from dualloop mode Figure 18 in that the feedback for PLL2 is driven by a clock output instead of the VCO output. Figure 20 illustrates the use case of nested zero-delay dual-loop mode. This configuration is similar to the dual PLL in Dual PLL, except that the feedback to the first PLL is driven by a clock output. This causes the clock outputs to have deterministic phase relationship with the clock input. Because all the clock outputs can be synchronized together, all the clock outputs can share the same deterministic phase relationship with the clock input signal. The feedback to PLL1 can be connected internally as shown using CLKout6, CLKout8, SYSREF, or externally using FBCLKin (CLKin1). It is also possible to use an external VCO in place of the PLL2 internal VCO; however, because CLKin1 must be used as Fin for the external VCO, it is unavailable as a reference to PLL1 or as external zero-delay feedback. LMK04821 includes VCO1 divider on VCO1 output. PLL1 PLL2 R N Phase Detector PLL1 External VCXO or Tunable Crystal External Loop Filter OSCout OSCout* OSCin CLKinX CLKinX* Up to 3 inputs CPout1 Up to 1 OSCout External Loop Filter CPout2 Divider Digital Delay Analog Delay R Input Buffer N Phase Detector PLL2 Partially Integrated Loop Filter Dual Internal VCOs Internal or external loopback, user programmable SDCLKoutY SDCLKoutY* 7 SYSREF or Device Clocks 7 blocks SYSREF Analog Delay Digital Delay 1 Global SYSREF Divider LMK0482x DCLKoutX DCLKoutX* 7 Device Clocks Figure 19. Simplified Functional Block Diagram for Cascaded Zero-Delay Dual-Loop Mode Table 6. Cascaded Zero-Delay Dual-Loop Mode Register Configuration FIELD REGISTER ADDRESS FUNCTION VALUE PLL1_NCLK_MUX 0x13F Selects the input to the PLL1 N divider 0 OSCin PLL2_NCLK_MUX 0x13F Selects the input to the PLL2 N divider 1 Feedback mux FB_MUX_EN 0x13F Enables the feedback mux. 1 Feedback mux enabled FB_MUX 0x13F Selects the output of the feedback mux. 0, 1, or 2 Select between DCLKout6, DCLKout8, SYSREF OSCin_PD 0x140 Powers down the OSCin port. 0 Powered up CLKin0_OUT_MUX 0x147 Selects where the output of CLKin0 is directed. 0 PLL1 CLKin1_OUT_MUX 0x147 Selects where the output of CLKin1 is directed. 0 or 2 Fin or PLL1 VCO_MUX 0x138 Selects the VCO 0, 1 or an external VCO 0 or 1 VCO 0 or VCO 1 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 SELECTED VALUE Submit Documentation Feedback 51 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com PLL1 PLL2 R N Phase Detector PLL1 External VCXO or Tunable Crystal External Loop Filter OSCout OSCout* OSCin CLKinX CLKinX* Up to 3 inputs CPout1 Up to 1 OSCout External Loop Filter CPout2 Divider Digital Delay Analog Delay R Input Buffer N Phase Detector PLL2 Partially Integrated Loop Filter Dual Internal VCOs Internal or external loopback, user programmable SDCLKoutY SDCLKoutY* 7 SYSREF or Device Clocks 7 blocks SYSREF Analog Delay Digital Delay 1 Global SYSREF Divider LMK0482x DCLKoutX DCLKoutX* 7 Device Clocks Figure 20. Simplified Functional Block Diagram for Nested Zero-Delay Dual-Loop Mode LMK04821 includes the VCO1 divider on the VCO1 output. Table 7 illustrates nested zero-delay mode. This is the same as cascaded, except the clock out feedback is to PLL1. The CLKin and CLKout have the same deterministic phase relationship, but the VCXO's phase is not deterministic to the CLKin or CLKouts. Table 7. Nested Zero-Delay Dual-Loop Mode Register Configuration FIELD REGISTER ADDRESS FUNCTION VALUE SELECTED VALUE PLL1_NCLK_MUX 0x13F Selects the input to the PLL1 N divider 1 Feedback mux PLL2_NCLK_MUX 0x13F Selects the input to the PLL2 N divider 0 PLL2 P FB_MUX_EN 0x13F Enables the feedback mux. 1 Enabled FB_MUX 0x13F Selects the output of the feedback mux. 0, 1, or 2 Select between DCLKout6, DCLKout8, SYSREF Powered up OSCin_PD 0x140 Powers down the OSCin port. 0 CLKin0_OUT_MUX 0x147 Selects where the output of CLKin0 is directed. 2 PLL1 CLKin1_OUT_MUX 0x147 Selects where the output of CLKin1 is directed. 0 or 2 Fin or PLL1 VCO_MUX 0x138 Selects the VCO 0, 1 or an external VCO 0 or 1 VCO 0 or VCO 1 52 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.4.3 Single-Loop Mode Figure 21 illustrates the use case of PLL2 single loop mode. When used with a clean high frequency reference on OSCin, performance can be comparable to (or even better than) dual-loop mode. Figure 21. Simplified Functional Block Diagram for Single-Loop Mode Table 8. Single-Loop Mode Register Configuration FIELD REGISTER ADDRESS FUNCTION VALUE SELECTED VALUE PLL1_NCLK_MUX 0x13F Selects the input to the PLL1 N divider X Don't care PLL2_NCLK_MUX 0x13F Selects the input to the PLL2 N divider 0 PLL2 P FB_MUX_EN 0x13F Enables the feedback mux. 0 Disabled FB_MUX 0x13F Selects the output of the feedback mux. 0, 1, or 2 Select between DCLKout6, DCLKout8, SYSREF OSCin_PD 0x140 Powers down the OSCin port. 0 Powered up PLL1_PD 0x140 Powers down PLL1. 1 Powered down CLKin0_OUT_MUX 0x147 Selects where the output of CLKin0 is directed. X Don't care CLKin1_OUT_MUX 0x147 Selects where the output of CLKin1 is directed. 3 Off VCO_MUX 0x138 Selects the VCO 0, 1 or an external VCO 0 or 1 VCO 0 or VCO 1 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 53 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.4.4 Single-Loop Mode With External VCO Adding an external VCO is possible using the CLKin1/Fin input port. The input may be single-ended or differential. At high frequency the input impedance to Fin is low, so a resistive pad is recommended for matching. Figure 22. Simplified Functional Block Diagram for Single-Loop Mode With External VCO Table 9. Single-Loop Mode With External VCO Register Configuration 54 FIELD REGISTER ADDRESS FUNCTION VALUE SELECTED VALUE PLL1_NCLK_MUX 0x13F Selects the input to the PLL1 N divider X Don't care PLL2_NCLK_MUX 0x13F Selects the input to the PLL2 N divider 0 PLL2_P FB_MUX_EN 0x13F Enables the feedback mux. 0 Disabled FB_MUX 0x13F Selects the output of the feedback mux. X Don't care OSCin_PD 0x140 Powers down the OSCin port. 0 Powered up VCO_LDO_PD 0x140 Powers down the VCO LDO. 1 Powered down VCO_PD 0x140 Powers down the VCO. 1 Powered down PLL1_PD 0x140 Powers down PLL1. 1 Powered down CLKin0_OUT_MUX 0x147 Selects where the output of CLKin0 is directed. X Don't care CLKin1_OUT_MUX 0x147 Selects where the output of CLKin1 is directed. 0 Fin VCO_MUX 0x138 Selects the VCO 0, 1 or an external VCO 2 External VCO Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.4.5 Distribution Mode Figure 23 illustrates the use case of distribution mode. As in all other use cases, OSCin to OSCout can be used as a buffer to OSCin or from clock distribution path via CLKout6, CLKout8, or the SYSREF divider. At high frequency the input impedance to Fin is low, so a resistive pad is recommended for matching. Figure 23. Simplified Functional Block Diagram for Distribution Mode Table 10. Distribution Mode Register Configuration FIELD REGISTER ADDRESS FUNCTION VALUE SELECTED VALUE PLL1_NCLK_MUX 0x13F Selects the input to the PLL1 N divider X Don't care PLL2_NCLK_MUX 0x13F Selects the input to the PLL2 N divider X Don't care FB_MUX_EN 0x13F Enables the feedback mux. 0 Disabled FB_MUX 0x13F Selects the output of the feedback mux. X Don't care OSCin_PD 0x140 Powers down the OSCin port. 1 Powered down VCO_LDO_PD 0x140 Powers down the VCO LDO. 1 Powered down VCO_PD 0x140 Powers down the VCO. 1 Powered down PLL1_PD 0x140 Powers down PLL1. 1 Powered down PLL2_PRE_PD 0x173 Powers down PLL2 prescaler. 1 Powered down PLL2_PD 0x173 Powers down PLL2. 1 Powered down CLKin0_OUT_MUX 0x147 Selects where the output of CLKin0 is directed. X Don't care CLKin1_OUT_MUX 0x147 Selects where the output of CLKin1 is directed. 0 Fin VCO_MUX 0x138 Selects the VCO 0, 1 or an external VCO 2 External VCO Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 55 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.5 Programming LMK0482x family devices are programmed using 24-bit registers. Each register consists of a 1-bit command field (R/W), a 2-bit multi-byte field (W1, W0), a 13-bit address field (A12 to A0), and an 8-bit data field (D7 to D0). The contents of each register is clocked in MSB first (R/W), and the LSB (D0) last. During programming, the CS* signal is held low. The serial data is clocked in on the rising edge of the SCK signal. After the LSB is clocked in, the CS* signal goes high to latch the contents into the shift register. TI recommends programming registers in numeric order - for example, 0x000 to 0x1FFF - to achieve proper device operation. Each register consists of one or more fields which control the device functionality. See Electrical Characteristics and Figure 1 for timing details. R/W bit = 0 is for SPI write. R/W bit = 1 is for SPI read. W1 and W0 should be written as 0. 9.5.1 Recommended Programming Sequence Registers are programmed in numeric order, with 0x000 being the first and 0x1FFF being the last register programmed. The recommended programming sequence from POR involves: 1. Program register 0x000 with RESET = 1. 2. Program registers in numeric order from 0x000 to 0x165. Ensure the following register is programmed as follows: - 0x145 = 127 (0x7F) 3. Program register 0x171 to 0xAA and 0x172 to 0x02. 4. If using LMK04821, program register 0x174. 5. Program registers 0x17C and 0x17D as required by OPT_REG_1 and OPT_REG_2. 6. Program registers 0x166 to 0x1FFF. When using LMK04821: Program register 0x174, bits 4:0 (VCO1_DIV) with the proper value before programming the PLL2_N register in 0x166, 0x167, and 0x168 for proper total PLL2_N value. Program register 0x171, 0x172, 0x17C (OPT_REG_1) and 0x17D (OPT_REG_2) before programming PLL2 in registers: 0x166, 0x167, and 0x168, to optimize PLL2_N and VCO1 phase-noise performance over temperature. 9.5.1.1 SPI LOCK When writing to SPI_LOCK, registers 0x1FFD, 0x1FFE, and 0x1FFF should all always be written sequentially. 9.5.1.2 SYSREF_CLR When using SYSREF output, SYSREF local digital delay block should be cleared using SYSREF_CLR bit. See SYSREF_CLR for more info. 9.5.1.3 RESET Pin If the RESET pin is not used during normal operation, TI recommends programming the RESET_TYPE register to an output setting, to prevent noise from spontaneously resetting the device. 56 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.6 Register Maps 9.6.1 Register Map for Device Programming Table 11 provides the register map for device programming. Any register can be read from the same data address it is written to. Table 11. LMK0482x Register Map ADDRESS [11:0] DATA 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 POWER DOWN 0x000 RESET 0 0 SPI_3WIRE _DIS 0x002 0 0 0 0 0x003 ID_DEVICE_TYPE 0x004 ID_PROD[15:8] 0x005 ID_PROD[7:0] 0x006 ID_MASKREV 0x00C ID_VNDR[15:8] 0x00D 0x100 ID_VNDR[7:0] 0 0x101 CLKout0_1 _ODL CLKout0_1 _IDL DCLKout0_DIV DCLKout0_DDLY_CNTH 0x103 DCLKout0_DDLY_CNTL DCLKout0_ ADLY_MUX DCLKout0_ADLY 0x104 0 DCLKout0 _HS SDCLKout1 _MUX 0x105 0 0 0 SDCLKout1_ ADLY_EN 0x106 DCLKout0 _ DDLY_PD DCLKout0 _ HSg_PD DCLKout0 _ ADLYg_PD DCLKout0 _ADLY _PD 0x107 SDCLKout1 _POL 0x108 0 0x109 SDCLKout1_ADLY CLKout0_1 _PD CLKout2_3 _IDL DCLKout2_DDLY_CNTL 0 DCLKout2 _HS SDCLKout3 _MUX 0x10D 0 0 0 SDCLKout3 _ ADLY_EN 0x10E DCLKout2 _ DDLY_PD DCLKout2 _ HSg_PD DCLKout2 _ ADLYg_PD DCLKout2 _ADLY _PD 0x10F SDCLKout3 _POL 0x110 0 CLKout2_3 _PD SDCLKout3 _PD CLKout2_FMT DCLKout4_DIV DCLKout4_DDLY_CNTL DCLKout4_ ADLY_MUX DCLKout4_ADLY 0x114 0 DCLKout4 _HS SDCLKout5 _MUX 0x115 0 0 0 SDCLKout5 _ ADLY_EN 0x116 DCLKout4 _ DDLY_PD DCLKout4 _ HSg_PD DCLKout4 _ ADLYg_PD DCLKout4 _ADLY _PD 0x117 SDCLKout5 _POL 0x118 0 CLKout6_8 _IDL SDCLKout3_DIS_MODE DCLKout2 _POL DCLKout4_DDLY_CNTH CLKout6_7 _ODL SDCLKout3 _HS SDCLKout3_ADLY CLKout4_5 _IDL CLKout5_FMT DCLKout2_MUX SDCLKout3_DDLY CLKout3_FMT 0x113 CLKout0_FMT DCLKout2_ ADLY_MUX 0x10C 0x111 SDCLKout1 _PD DCLKout2_DIV DCLKout2_ADLY CLKout4_5 _ODL SDCLKout1_DIS_MODE DCLKout0 _POL DCLKout2_DDLY_CNTH 0x10B SDCLKout1 _HS SDCLKout1_DDLY CLKout1_FMT CLKout2_3 _ODL DCLKout0_MUX DCLKout4_MUX SDCLKout5 _HS SDCLKout5_DDLY SDCLKout5_ADLY CLKout4_5 _PD SDCLKout5_DIS_MODE DCLKout4 _POL SDCLKout5 _PD CLKout4_FMT DCLKout6_DIV Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 57 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Register Maps (continued) Table 11. LMK0482x Register Map (continued) ADDRESS [11:0] DATA 7 0x119 6 5 0 DCLKout6 _HS SDCLKout7 _MUX 0x11D 0 0 0 SDCLKout7 _ ADLY_EN 0x11E DCLKout6 _ DDLY_PD DCLKout6 _ HSg_PD DCLKout6 _ ADLYg_PD DCLKout6 _ADLY _PD 0x11F SDCLKout7 _POL 0x120 0 0x121 CLKout6_7 _PD DCLKout8_DDLY_CNTL 0 DCLKout8 _HS SDCLKout9 _MUX 0x125 0 0 0 SDCLKout9 _ ADLY_EN 0x126 DCLKout8 _ DDLY_PD DCLKout8 _ HSg_PD DCLKout8 _ ADLYg_PD DCLKout8 _ADLY _PD 0x127 SDCLKout9 _POL 0x128 0 SDCLKout9_ADLY CLKout8_9 _PD CLKout10 _11_IDL SDCLKout9_DIS_MODE CLKout8_FMT DCLKout10_DDLY_CNTL DCLKout10 _ ADLY_MUX 0x12C 0 DCLKout10 _HS SDCLKout11 _MUX 0x12D 0 0 0 SDCKLout11 _ ADLY_EN 0x12E DCLKout10 _ DDLY_PD DCLKout10 _ HSg_PD DLCLKout10 _ ADLYg_PD DCLKout10 _ ADLY_PD 0x12F SDCLKout11 _POL 0x130 0 DCLKout10_MUX SDCLKout11 _HS SDCLKout11_DDLY SDCLKout11_ADLY CLKout10 _11_PD SDCLKout11_DIS_MODE DCLKout10 _POL CLKout11_FMT CLKout12 _13_IDL SDCLKout11 _PD CLKout10_FMT DCLKout12_DIV DCLKout12_DDLY_CNTH DCLKout12_DDLY_CNTL DCLKout12_ ADLY_MUX DCLKout12_ADLY 0x134 0 DCLKout12 _HS SDCLKout13 _MUX 0x135 0 0 0 SDCLKout13 _ ADLY_EN 0x136 DCLKout12 _ DDLY_PD DCLKout12 _ HSg_PD DCLKout12 _ ADLYg_PD DCLKout12 _ ADLY_PD 0x137 SDCLKout13 _POL 0x138 0 0x139 0 0 0 0x13A 0 0 0 DCLKout12_MUX SDCLKout13 _HS SDCLKout13_DDLY SDCLKout13_ADLY CLKout12 _13_PD SDCLKout13_DIS_MODE DCLKout12 _POL CLKout13_FMT 0 SDCLKout13 _PD CLKout12_FMT OSCout _MUX 0x13B SDCLKout9 _PD DCLKout10_DIV DCLKout10_ADLY VCO_MUX SDCLKout9 _HS DCLKout8 _POL CLKout9_FMT 0x133 DCLKout8_MUX SDCLKout9_DDLY DCLKout10_DDLY_CNTH 0x131 SDCLKout7 _PD CLKout6_FMT DCLKout8 _ ADLY_MUX 0x124 CLKout12 _13 _ODL SDCLKout7_DIS_MODE DCLKout8_DIV DCLKout8_ADLY 0x12B SDCLKout7 _HS DCLKout6 _POL DCLKout8_DDLY_CNTH 0x129 DCLKout6_MUX SDCLKout7_ADLY CLKout8_9 _IDL CLKout10 _11 _ODL 0 SDCLKout7_DDLY CLKout7 _FMT 0x123 1 DCLKout6_ ADLY_MUX DCLKout6_ADLY CLKout8_9 _ODL 2 DCLKout6_DDLY_CNTL 0x11C 0x13C 3 DCLKout6_DDLY_CNTH 0x11B 58 4 OSCout_FMT 0 SYSREF_ CLKin0_MUX SYSREF_MUX SYSREF_DIV[12:8] SYSREF_DIV[7:0] 0 0 Submit Documentation Feedback 0 SYSREF_DDLY[12:8] Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Register Maps (continued) Table 11. LMK0482x Register Map (continued) ADDRESS [11:0] DATA 7 6 5 4 0x13D 0x13E 3 2 1 0 SYSREF_DDLY[7:0] 0 0 0 0 0 PLL1_NCLK _MUX 0 SYSREF_PULSE_CNT 0x13F 0 0 0 PLL2_NCLK _MUX FB_MUX _EN 0x140 PLL1_PD VCO_LDO_PD VCO_PD OSCin_PD SYSREF_GBL _PD SYSREF_PD SYSREF _DDLY_PD SYSREF _PLSR_PD 0x141 DDLYd_ SYSREF_EN DDLYd12 _EN DDLYd10 _EN DDLYd7_EN DDLYd6_EN DDLYd4_EN DDLYd2_EN DDLYd0_EN 0 SYNC_PLL1 _DLD SYNC_DIS4 FB_MUX 0x142 0 0 0x143 SYSREF_DDLY _CLR SYNC_1SHOT _EN SYNC_POL SYNC_EN SYNC_PLL2 _DLD 0x144 SYNC _DISSYSREF SYNC_DIS12 SYNC_DIS10 SYNC_DIS8 SYNC_DIS6 0x145 0 1 1 1 1 1 1 1 0x146 0 0 CLKin2_EN CLKin1_EN CLKin0_EN CLKin2_TYPE CLKin1_TYPE CLKin0_TYPE 0x147 CLKin_SEL _POL 0x148 0 0 CLKin_SEL0_MUX CLKin_SEL0_TYPE 0x149 0 SDIO_RDBK _TYPE CLKin_SEL1_MUX CLKin_SEL1_TYPE 0x14A 0 0 RESET_MUX 0x14B DDLYd_STEP_CNT CLKin_SEL_MODE LOS_TIMEOUT LOS_EN 0x14E TRACK_EN DAC_CLK_CNTR 0x151 0 0 0 HOLDOVER _ PLL1_DET 0 0 0 0 CLKin1_R[13:8] CLKin1_R[7:0] 0 0 CLKin2_R[13:8] CLKin2_R[7:0] 0 0 PLL1_N[13:8] 0x15A PLL1_N[7:0] PLL1_WND_SIZE 0 PLL1 _CP_TRI PLL1 _CP_POL PLL1_CP_GAIN 0 PLL1_DLD_CNT[13:8] 0x15D PLL1_DLD_CNT[7:0] 0 0 0x15F PLL1_R_DLY PLL1_N_DLY PLL1_LD_MUX 0 0 0 PLL1_LD_TYPE 0 0x161 PLL2_R[11:8] PLL2_R[7:0] 0x162 0x163 HOLDOVER _EN CLKin0_R[13:8] 0x158 0x160 HOLDOVER _HITLESS _SWITCH CLKin0_R[7:0] 0x156 0x15E HOLDOVER _VTUNE_DET HOLDOVER_DLD_CNT[7:0] 0x154 0x15C HOLDOVER _LOS _DET HOLDOVER_DLD_CNT[13:8] 0x152 0x15B MAN_DAC[9:8] DAC_TRIP_HIGH CLKin _OVERRIDE 0x159 MAN_DAC _EN DAC_TRIP_LOW DAC_CLK_MULT 0 0x157 CLKin0_OUT_MUX RESET_TYPE HOLDOVER _ FORCE 0 0x150 0x155 SYNC_DIS0 MAN_DAC[7:0] 0 0x14F 0x153 SYNC_DIS2 CLKin1_OUT_MUX 0x14C 0x14D SYNC_MODE PLL2_P 0 PLL2 _XTAL_EN OSCin_FREQ 0 0 0 0 0x164 PLL2_N_CAL[15:8] 0x165 PLL2_N_CAL[7:0] Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 0 PLL2 _REF_2X_EN PLL2_N_CAL[17:16] Submit Documentation Feedback 59 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Register Maps (continued) Table 11. LMK0482x Register Map (continued) ADDRESS [11:0] 0x166 DATA 7 0 6 5 0 0 0 0x167 PLL2_N[15:8] 0x168 PLL2_N[7:0] 0x169 0 0x16A 0 SYSREF_REQ_ EN PLL2_WND_SIZE 0 0 3 2 0 PLL2_FCAL _DIS 1 PLL2 _CP_POL PLL2_CP_GAIN 0 PLL2_N[17:16] PLL 2_CP_TRI 1 PLL2_DLD_CNT[15:8] 0x16B 0x16C PLL2_DLD_CNT[7:0] 0x16D PLL2_LF_R4 PLL2_LF_R3 PLL2_LF_C4 0x16E PLL2_LF_C3 PLL2_LD_MUX PLL2_LD_TYPE 0x171 1 0 1 0 1 0 1 0 0x172 0 0 0 0 0 0 1 0 0x173 0 PLL2_PRE_PD PLL2_PD 0 0 0 0 0 0x174 0 0 0 VCO1_DIV 0x17C OPT_REG_1 0x17D OPT_REG_2 0x182 0 0 0 0 0 RB_PLL1_ LD_LOST RB_PLL1_LD CLR_PLL1_ LD_LOST 0x183 0 0 0 0 0 RB_PLL2_ LD_LOST RB_PLL2_LD CLR_PLL2_ LD_LOST RB_CLKin2_ SEL RB_CLKin1_ SEL RB_CLKin0_ SEL X RB_CLKin1_ LOS RB_CLKin0_ LOS 0 RB_ HOLDOVER X X X 0x184 RB_DAC_VALUE[9:8] 0x185 0x188 60 4 RB_DAC_VALUE[7:0] 0 0 X 0x1FFD SPI_LOCK[23:16] 0x1FFE SPI_LOCK[15:8] 0x1FFF SPI_LOCK[7:0] Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7 Device Register Descriptions The following section details the fields of each register, the power-on reset defaults, and specific descriptions of each bit. In some cases, similar fields are located in multiple registers. In this case, specific outputs may be designated as X or Y. In these cases, the X represents even numbers from 0 to 12, and the Y represents odd numbers from 1 to 13. In the case where X and Y are both used in a bit name, then Y = X + 1. 9.7.1 System Functions 9.7.1.1 RESET, SPI_3WIRE_DIS This register contains the RESET function, and a setting to disable 3-wire SPI mode. Table 12. Register 0x000 BIT NAME POR DEFAULT 7 RESET 0 0: Normal operation 1: Reset (automatically cleared) 6:5 NA 0 Reserved 4 SPI_3WIRE_DIS 0 Disable 3-wire SPI mode. 4-wire SPI mode is enabled by selecting SPI Read back in one of the output MUX settings. For example, CLKin0_SEL_MUX. 0: 3-wire mode enabled 1: 3-wire mode disabled 3:0 NA NA DESCRIPTION Reserved 9.7.1.2 POWERDOWN This register contains the POWERDOWN function. Table 13. Register 0x002 BIT NAME POR DEFAULT 7:1 NA 0 Reserved 0 POWERDOWN 0 0: Normal operation 1: Powerdown DESCRIPTION 9.7.1.3 ID_DEVICE_TYPE This register contains the product device type. This is read only register. Table 14. Register 0x003 BIT NAME POR DEFAULT 7:0 ID_DEVICE_TYPE 6 DESCRIPTION PLL product device type Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 61 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.1.4 ID_PROD[15:8], ID_PROD These registers contain the product identifier. This is a read only register. Table 15. ID_PROD Register Configuration, ID_PROD[15:0] MSB LSB 0x004[7:0] 0x005[7:0] BIT REGISTERS FIELD NAME POR DEFAULT 7:0 0x004 ID_PROD[15:8] 208 MSB of the product identifier 7:0 0x005 ID_PROD 91 LSB of the product identifier DESCRIPTION 9.7.1.5 ID_MASKREV This register contains the IC version identifier. This is a read only register. Table 16. Register 0x006 POR DEFAULT BIT NAME 7:0 ID_MASKREV DESCRIPTION 36 IC version identifier for LMK04821 37 IC version identifier for LMK04826 32 IC version identifier for LMK04828 9.7.1.6 ID_VNDR[15:8], ID_VNDR These registers contain the vendor identifier. This is a read only register. Table 17. ID_VNDR Register Configuration, ID_VNDR[15:0] MSB LSB 0x00C[7:0] 0x00D[7:0] Table 18. Registers 0x00C, 0x00D BIT REGISTERS NAME POR DEFAULT 7:0 0x00C ID_VNDR[15:8] 81 MSB of the vendor identifier 7:0 0x00D ID_VNDR 4 LSB of the vendor identifier 62 Submit Documentation Feedback DESCRIPTION Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.2 (0x100 - 0x138) Device Clock and SYSREF Clock Output Controls 9.7.2.1 CLKoutX_Y_ODL, CLKoutX_Y_IDL, DCLKoutX_DIV These registers control the input and output drive level, as well as the device clock out divider values. Table 19. Registers 0x100, 0x108, 0x110, 0x118, 0x120, 0x128, and 0x130 BIT NAME POR DEFAULT 7 NA 0 Reserved 6 CLKoutX_Y_ODL 0 Output drive level. Setting this bit increases the current to the CLKoutX_Y output buffers, which can slightly improve noise floor. 5 CLKoutX_Y_IDL 0 Input drive level. Setting this bit increases the current to the clock distribution buffer sourcing CLKoutX_Y, which can slightly improve noise floor. 4:0 (1) DCLKoutX_DIV X=02 X=24 X=48 X=68 X=88 X = 10 8 X = 12 2 DESCRIPTION DCLKoutX_DIV sets the divide value for the clock output; the divide may be even or odd. Both even or odd divides output a 50% duty cycle clock if duty cycle correction (DCC) is selected. Divider is unused if DCLKoutX_MUX = 2 (bypass), equivalent divide of 1. Field Value Divider Value 0 (0x00) 32 1 (0x01) 1 (1) 2 (0x02) 2 ... ... 30 (0x1E) 30 31 (0x1F) 31 Not valid if DCLKoutX_MUX = 0, divider only. Not valid if DCLKoutX_MUX = 3 (analog delay + divider) and DCLKoutX_ADLY_MUX = 0 (without duty cycle correction/halfstep). 9.7.2.2 DCLKoutX_DDLY_CNTH, DCLKoutX_DDLY_CNTL This register controls the digital delay high and low count values for the device clock outputs. Table 20. Registers 0x101, 0x109, 0x111, 0x119, 0x121, 0x129, 0x131 BIT NAME POR DEFAULT DESCRIPTION Number of clock cycles the output is high when digital delay is engaged. Field Value 7:4 DCLKoutX _DDLY_CNTH 5 Delay Values 0 (0x00) 16 1 (0x01) Reserved 2 (0x02) 2 ... ... 15 (0x0F) 15 Number of clock cycles the output is low when dynamic digital delay is engaged. Field Value 3:0 DCLKoutX _DDLY_CNTL 5 Delay Values 0 (0x00) 16 1 (0x01) Reserved 2 (0x02) 2 ... ... 15 (0x0F) 15 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 63 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.2.3 DCLKoutX_ADLY, DCLKoutX_ADLY_MUX, DCLKout_MUX These registers control the analog delay properties for the device clocks. Table 21. Registers 0x103, 0x10B, 0x113, 0x11B, 0x123, 0x12B, 0x133 BIT POR DEFAULT NAME DESCRIPTION Device clock analog delay value. Delay step size is 25 ps. DCLKoutX_ADLY_PD = 0 (DCLK analog delay powered up) also adds a fixed 500-ps delay. Effective range is 500 ps to 1075 ps. 7:3 DCLKoutX_ALDY DCLKoutX_ADLY _MUX 2 0 Field Value Delay Value 0 (0x00) 0 ps 1 (0x01) 25 ps 2 (0x02) 50 ps ... ... 23 (0x17) 575 ps This register selects the input to the analog delay for the device clock. Used when DCLKoutX_MUX = 3. 0: Divided without duty cycle correction or half step. (1) 1: Divided with duty cycle correction and half step. 0 This selects the input to the device clock buffer. Field Value Mux Output 0 (0x0) 1:0 (1) DCLKoutX_MUX 0 Divider only (1) 1 (0x1) Divider with duty cycle Correction and half step 2 (0x2) Bypass 3 (0x3) Analog delay + divider DCLKoutX_DIV = 1 is not valid when DCLKoutX_MUX = 0. DCLKoutX_DIV = 1 is valid for DCLKoutX_MUX = 1, or DCLKoutX_MUX = 3 and DCLKoutX_ADLY_MUX = 1. 9.7.2.4 DCLKoutX_HS, SDCLKoutY_MUX, SDCLKoutY_DDLY, SDCLKoutY_HS These registers set the half step for the device clock, the SYSREF output MUX, the SYSREF clock digital delay, and half step. Table 22. Registers 0x104, 0x10C, 0x114, 0x11C, 0x124, 0x12C, 0x134 BIT NAME POR DEFAULT 7 NA 0 Reserved 6 DCLKoutX_HS 0 Sets the device clock half step value. Half step must be zero (0) for a divide of 1. 0: 0 cycles 1: -0.5 cycles 5 SDCLKoutY_MUX 0 Sets the input the the SDCLKoutX outputs. 0: Device clock output 1: SYSREF output DESCRIPTION Sets the number of VCO cycles to delay the SDCLKout by. 4:1 0 64 SDCLKoutY_DDLY SDCLKoutY_HS Submit Documentation Feedback 0 0 Field Value Delay Cycles 0 (0x00) Bypass 1 (0x01) 2 2 (0x02) 3 ... ... 10 (0x0A) 11 11 to 15 (0x0B to 0x0F) Reserved Sets the SYSREF clock half-step value. 0: 0 cycles 1: -0.5 cycles Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.2.5 SDCLKoutY_ADLY_EN, SDCLKoutY_ADLY These registers set the analog delay parameters for the SYSREF outputs. Table 23. Registers 0x105, 0x10D, 0x115, 0x11D, 0x125, 0x12D, 0x135 BIT NAME POR DEFAULT 7:5 NA 0 Reserved 4 SDCLKoutY _ADLY_EN 0 Enables analog delay for the SYSREF output. 0: Disabled 1: Enabled DESCRIPTION Sets the analog delay value for the SYSREF output. Step size is 150 ps, except first step (600 ps). SDCLKoutY_ADLY_EN = 1 (SDCLK analog delay enabled) also adds a fixed 700-ps delay. Effective range is 700 ps to 2950 ps. 3:0 SDCLKoutY _ADLY 0 Field Value Delay Value 0 (0x0) 0 ps 1 (0x1) 600 ps 2 (0x2) 750 ps (+150 ps from 0x1) 3 (0x3) 900 ps (+150 ps from 0x2) ... ... 14 (0xE) 2100 ps (+150 ps from 0xD) 15 (0xF) 2250 ps (+150 ps from 0xE) Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 65 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.2.6 DCLKoutX_DDLY_PD, DCLKoutX_HSg_PD, DCLKout_ADLYg_PD, DCLKout_ADLY_PD, DCLKoutX_Y_PD, SDCLKoutY_DIS_MODE, SDCLKoutY_PD This register controls the power-down functions for the digital delay, glitchless half step, glitchless analog delay, analog delay, outputs, and SYSREF disable modes. Table 24. Registers 0x106, 0x10E, 0x116, 0x11E, 0x126, 0x12E, 0x136 BIT NAME POR DEFAULT DESCRIPTION 7 DCLKoutX _DDLY_PD 0 Powerdown the device clock digital delay circuitry. 0: Enabled 1: Powerdown 6 DCLKoutX _HSg_PD 1 Powerdown the device clock glitchless half-step feature. 0: Enabled 1: Powerdown 5 DCLKoutX _ADLYg_PD 1 Powerdown the device clock glitchless analog delay feature. 0: Enabled, analog delay step size of one code is glitchless between values 1 to 23. 1: Powerdown 4 DCLKoutX _ADLY_PD 1 Powerdown the device clock analog delay feature. 0: Enabled 1: Powerdown CLKoutX_Y_PD X_Y = 0_1 1 X_Y = 2_3 1 X_Y = 4_5 0 X_Y = 6_7 0 X_Y = 8_9 0 X_Y = 10_11 0 X_Y = 12_13 1 3 Powerdown the clock group defined by X and Y. 0: Enabled 1: Powerdown Configures the output state of the SYSREF Field Value 2:1 0 (1) 66 SDCLKoutY _DIS_MODE SDCLKoutY_PD 0 1 Disable Mode 0 (0x00) Active in normal operation 1 (0x01) If SYSREF_GBL_PD = 1, the output is a logic low, otherwise it is active. 2 (0x02) If SYSREF_GBL_PD = 1, the output is a nominal Vcm voltage (1), otherwise it is active. 3 (0x03) Output is a nominal Vcm voltage (1) Powerdown SDCLKoutY and set to the state defined by SDCLKoutY_DIS_MODE If LVPECL mode is used with emitter resistors to ground, the output Vcm is ~0 V, and each pin is ~0 V. Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.2.7 SDCLKoutY_POL, SDCLKoutY_FMT, DCLKoutX_POL, DCLKoutX_FMT These registers configure the output polarity, and format. Table 25. Registers 0x107, 0x10F, 0x117, 0x11F, 0x127, 0x12F, 0x137 BIT 7 NAME SDCLKoutY_POL POR DEFAULT DESCRIPTION Sets the polarity of clock on SDCLKoutY when device clock output is selected with SDCLKoutY_MUX. 0: Normal 1: Inverted 0 Sets the output format of the SYSREF clocks 6:4 3 SDCLKoutY_FMT DCLKoutX_POL 0 Field Value Output Format 0 (0x00) Powerdown 1 (0x01) LVDS 2 (0x02) HSDS 6 mA 3 (0x03) HSDS 8 mA 4 (0x04) HSDS 10 mA 5 (0x05) LVPECL 1600 mV 6 (0x06) LVPECL 2000 mV 7 (0x07) LCPECL Sets the polarity of the device clocks from the DCLKoutX outputs 0: Normal 1: Inverted 0 Sets the output format of the device clocks. 2:0 DCLKoutX_FMT LMK04821: 0 LMK04826/ LMK04828: X=00 X=20 X=41 X=61 X=81 X = 10 1 X = 12 0 Field Value Output Format 0 (0x00) Powerdown 1 (0x01) LVDS 2 (0x02) HSDS 6 mA 3 (0x03) HSDS 8 mA 4 (0x04) HSDS 10 mA 5 (0x05) LVPECL 1600 mV 6 (0x06) LVPECL 2000 mV 7 (0x07) LCPECL Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 67 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.3 SYSREF, SYNC, and Device Config 9.7.3.1 VCO_MUX, OSCout_MUX, OSCout_FMT This register selects the clock distribution source, and OSCout parameters. Table 26. Register 0x138 BIT NAME POR DEFAULT 7 NA 0 DESCRIPTION Reserved Selects clock distribution path source from VCO0, VCO1, or CLKin (external VCO) 6:5 4 VCO_MUX OSCout_MUX 0 0 Field Value VCO Selected 0 (0x00) VCO 0 1 (0x01) VCO 1 2 (0x02) CLKin1 (external VCO) 3 (0x03) Reserved Select the source for OSCout: 0: Buffered OSCin 1: Feedback mux Selects the output format of OSCout. When powered down, these pins may be used as CLKin2. 3:0 (1) 68 OSCout_FMT 4 Field Value OSCout Format 0 (0x00) Powerdown (CLKin2) 1 (0x01) LVDS 2 (0x02) Reserved 3 (0x03) Reserved 4 (0x04) LVPECL 1600 mVpp (1) 5 (0x05) LVPECL 2000 mVpp (1) 6 (0x06) LVCMOS (Norm / Inv) 7 (0x07) LVCMOS (Inv / Norm) 8 (0x08) LVCMOS (Norm / Norm) 9 (0x09) LVCMOS (Inv / Inv) 10 (0x0A) LVCMOS (Off / Norm) 11 (0x0B) LVCMOS (Off / Inv) 12 (0x0C) LVCMOS (Norm / Off) 13 (0x0D) LVCMOS (Inv / Off) 14 (0x0E) LVCMOS (Off / Off) When set to an LVPECL drive format, OSCout emitter resistors must be 240 to GND. Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.3.2 SYSREF_CLKin0_MUX, SYSREF_MUX This register sets the source for the SYSREF outputs. Refer to Figure 13 and SYNC/SYSREF. Table 27. Register 0x139 BIT NAME POR DEFAULT 7:3 NA 0 DESCRIPTION Reserved Selects the SYSREF output from SYSREF_MUX or CLKin0 direct 2 SYSREF_ CLKin0_MUX Field Value 0 SYSREF Source 0 SYSREF Mux 1 CLKin0 direct (from CLKin0_OUT_MUX) Selects the SYSREF source. 1:0 SYSREF_MUX 0 Field Value SYSREF Source 0 (0x00) Normal SYNC 1 (0x01) Re-clocked 2 (0x02) SYSREF pulser 3 (0x03) SYSREF continuous Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 69 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.3.3 SYSREF_DIV[12:8], SYSREF_DIV[7:0] These registers set the value of the SYSREF output divider. Table 28. Registers 0x13A, 0x13B MSB LSB 0x13A[4:0] 0x13B[7:0] BIT REGISTERS NAME POR DEFAULT 7:5 0x13A NA 0 DESCRIPTION Reserved Divide value for the SYSREF outputs. 4:0 7:0 0x13A SYSREF_DIV[12:8] 0x13B SYSREF_DIV[7:0] 12 0 Field Value Divide Value 0x00 to 0x07 Reserved 8 (0x08) 8 9 (0x09) 9 ... ... 8190 (0x1FFE) 8190 8191 (0X1FFF) 8191 9.7.3.4 SYSREF_DDLY[12:8], SYSREF_DDLY[7:0] These registers set the delay of the SYSREF digital delay value. Table 29. SYSREF Digital Delay Register Configuration, SYSREF_DDLY[12:0] MSB LSB 0x13C[4:0] 0x13D[7:0] BIT REGISTERS NAME POR DEFAULT 7:5 0x13C NA 0 DESCRIPTION Reserved Sets the value of the SYSREF digital delay. 4:0 7:0 70 0x13C 0x13D SYSREF_DDLY[12:8] SYSREF_DDLY[7:0] Submit Documentation Feedback 0 8 Field Value Delay Value 0x00 to 0x07 Reserved 8 (0x08) 8 9 (0x09) 9 ... ... 8190 (0x1FFE) 8190 8191 (0X1FFF) 8191 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.3.5 SYSREF_PULSE_CNT This register sets the number of SYSREF pulses if SYSREF is not in continuous mode. See SYSREF_CLKin0_MUX, SYSREF_MUX for further description of SYSREF's outputs. Programming the register causes the specified number of pulses to be output if "SYSREF Pulses" is selected by SYSREF_MUX and SYSREF functionality is powered up. Table 30. Register 0x13E BIT NAME POR DEFAULT 7:2 NA 0 DESCRIPTION Reserved Sets the number of SYSREF pulses generated when not in continuous mode. See SYSREF_CLKin0_MUX, SYSREF_MUX for more information on SYSREF modes. Field Value 1:0 SYSREF_PULSE_CNT 3 Number of Pulses 0 (0x00) 1 pulse 1 (0x01) 2 pulses 2 (0x02) 4 pulses 3 (0x03) 8 pulses 9.7.3.6 PLL2_NCLK_MUX, PLL1_NCLK_MUX, FB_MUX, FB_MUX_EN This register controls the feedback feature. Table 31. Register 0x13F BIT NAME POR DEFAULT 7:5 NA 0 Reserved 4 PLL2_NCLK_MUX 0 Selects the input to the PLL2 N divider 0: PLL prescaler 1: Feedback mux 3 PLL1_NCLK_MUX 0 Selects the input to the PLL1 N delay 0: OSCin 1: Feedback mux DESCRIPTION When in zero-delay mode, the feedback mux selects the clock output to be fed back into the PLL1 N divider. 2:1 0 FB_MUX FB_MUX_EN 0 0 Field Value Source 0 (0x00) DCLKout6 1 (0x01) DCLKout8 2 (0x02) SYSREF Divider 3 (0x03) External When using zero-delay, FB_MUX_EN must be set to 1 to power up the feedback mux. 0: Feedback mux powered down 1: Feedback mux enabled Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 71 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.3.7 PLL1_PD, VCO_LDO_PD, VCO_PD, OSCin_PD, SYSREF_GBL_PD, SYSREF_PD, SYSREF_DDLY_PD, SYSREF_PLSR_PD This register contains powerdown controls for OSCin and SYSREF functions. Table 32. Register 0x140 BIT NAME POR DEFAULT 7 PLL1_PD 0 Powerdown PLL1 0: Normal operation 1: Powerdown 6 VCO_LDO_PD 0 Powerdown VCO_LDO 0: Normal operation 1: Powerdown 5 VCO_PD 0 Powerdown VCO 0: Normal operation 1: Powerdown 4 OSCin_PD 0 Powerdown the OSCin port. 0: Normal operation 1: Powerdown 0 Powerdown individual SYSREF outputs depending on the setting of SDCLKoutY_DIS_MODE for each SYSREF output. SYSREF_GBL_PD allows many SYSREF outputs to be controlled through a single bit. 0: Normal operation 1: Activate powerdown mode 1 Powerdown the SYSREF circuitry and divider. If powered down, SYSREF output mode cannot be used. SYNC cannot be provided either. 0: SYSREF can be used as programmed by individual SYSREF output registers. 1: Powerdown 3 2 SYSREF_GBL_PD SYSREF_PD DESCRIPTION 1 SYSREF_DDLY_PD 1 Powerdown the SYSREF digital delay circuitry. 0: Normal operation, SYSREF digital delay may be used. Must be powered up during SYNC for deterministic phase relationship with other clocks. 1: Powerdown 0 SYSREF_PLSR_PD 1 Powerdown the SYSREF pulse generator. 0: Normal operation 1: Powerdown 9.7.3.8 DDLYdSYSREF_EN, DDLYdX_EN This register enables dynamic digital delay for enabled device clocks and SYSREF when DDLYd_STEP_CNT is programmed. Table 33. Register 0x141 BIT NAME POR DEFAULT 7 DDLYd _SYSREF_EN 0 Enables dynamic digital delay on SYSREF outputs 6 DDLYd12_EN 0 Enables dynamic digital delay on DCLKout12 5 DDLYd10_EN 0 Enables dynamic digital delay on DCLKout10 4 DDLYd8_EN 0 Enables dynamic digital delay on DCLKout8 3 DDLYd6_EN 0 Enables dynamic digital delay on DCLKout6 2 DDLYd4_EN 0 Enables dynamic digital delay on DCLKout4 1 DDLYd2_EN 0 Enables dynamic digital delay on DCLKout2 0 DDLYd0_EN 0 Enables dynamic digital delay on DCLKout0 72 Submit Documentation Feedback DESCRIPTION 0: Disabled 1: Enabled Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.3.9 DDLYd_STEP_CNT This register sets the number of dynamic digital delay adjustments occur. Upon programming, the dynamic digital delay adjustment begins for each clock output with dynamic digital delay enabled. Dynamic digital delay can only be started by SPI. Other registers must be set: SYNC_MODE = 3 Table 34. Register 0x142 BIT NAME POR DEFAULT 7:4 NA 0 DESCRIPTION Reserved Sets the number of dynamic digital delay adjustments that occur. 3:0 DDLYd_STEP_CNT 0 Field Value SYNC Generation 0 (0x00) No adjust 1 (0x01) 1 step 2 (0x02) 2 steps 3 (0x03) 3 steps ... ... 14 (0x0E) 14 steps 15 (0x0F) 15 steps Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 73 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.3.10 SYSREF_CLR, SYNC_1SHOT_EN, SYNC_POL, SYNC_EN, SYNC_PLL2_DLD, SYNC_PLL1_DLD, SYNC_MODE This register sets general SYNC parameters such as polarization, and mode. Refer to Figure 13 for block diagram. Refer to Table 1 for using SYNC_MODE for specific SYNC use cases. Table 35. Register 0x143 BIT 7 NAME SYSREF_CLR POR DEFAULT DESCRIPTION 1 Resets and arms the SDCLKoutY_DDLY path, allowing local digital delays to take effect after a SYNC event. Except during the SYSREF setup procedure (see SYNC/SYSREF), this bit should always be programmed to 0. While this bit is set, extra current is used. Refer to Table 87. 6 SYNC_1SHOT_EN 0 SYNC one shot enables edge-sensitive SYNC. 0: SYNC is level sensitive and outputs are held in SYNC while SYNC is asserted. 1: SYNC is edge sensitive, outputs are SYNCed on rising edge of SYNC. This results in the clock being held in SYNC for a minimum amount of time. 5 SYNC_POL 0 Sets the polarity of the SYNC pin. 0: Normal 1: Inverted 4 SYNC_EN 1 Enables the SYNC functionality. 0: Disabled 1: Enabled 3 SYNC_PLL2_DLD 0 0: Off 1: Assert SYNC until PLL2 DLD = 1 2 SYNC_PLL1_DLD 0 0: Off 1: Assert SYNC until PLL1 DLD = 1 Sets the method of generating a SYNC event. Field Value 1:0 74 SYNC_MODE 1 Submit Documentation Feedback SYNC Generation 0 (0x00) Prevents SYNC pin, SYNC_PLL1_DLD flag, or SYNC_PLL2_DLD flag from generating a SYNC event. 1 (0x01) SYNC event generated from SYNC pin or, if enabled, the SYNC_PLL1_DLD flag or SYNC_PLL2_DLD flag. 2 (0x02) For use with pulser - SYNC/SYSREF pulses are generated by pulser block through the SYNC pin or, if enabled, the SYNC_PLL1_DLD flag or SYNC_PLL2_DLD flag. 3 (0x03) For use with pulser - SYNC/SYSREF pulses are generated by pulser block when programming register 0x13E (SYSREF_PULSE_CNT) is written to (see SYSREF Pulser). Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.3.11 SYNC_DISSYSREF, SYNC_DISX SYNC_DISX prevents a clock output from being synchronized or interrupted by a SYNC event, or when outputting SYSREF. Table 36. Register 0x144 BIT NAME POR DEFAULT 7 SYNC_DISSYSREF 0 6 SYNC_DIS12 0 5 SYNC_DIS10 0 4 SYNC_DIS8 0 3 SYNC_DIS6 0 2 SYNC_DIS4 0 1 SYNC_DIS2 0 0 SYNC_DIS0 0 DESCRIPTION Prevents the SYSREF clocks from becoming synchronized during a SYNC event. If SYNC_DISSYSREF is enabled, it continues to operate normally during a SYNC event. Prevents the device clock output from becoming synchronized during a SYNC event or SYSREF clock. If SYNC_DIS bit for a particular output is enabled, then it continues to operate normally during a SYNC event or SYSREF clock. 9.7.3.12 Fixed Registers (0x145, 0x171 - 0x172) Always program this register to value 127. Table 37. Register 0x145 BIT NAME POR DEFAULT 7:0 Fixed Register 0 DESCRIPTION Always program to 127 Always program this register to value 170. Table 38. Register 0x171 BIT NAME POR DEFAULT 7:0 Fixed Register 10 (0x0A) DESCRIPTION Always program to 170 (0xAA) Always program this register to value 2. Table 39. Register 0x172 BIT NAME POR DEFAULT 7:0 Fixed Register 0 DESCRIPTION Always program to 2 (0x02) 9.7.4 (0x146 - 0x149) CLKin Control 9.7.4.1 CLKin2_EN, CLKin1_EN, CLKin0_EN, CLKin2_TYPE, CLKin1_TYPE, CLKin0_TYPE This register has CLKin enable and type controls. Table 40. Register 0x146 BIT NAME POR DEFAULT 7:6 NA 0 Reserved 5 CLKin2_EN 0 Enable CLKin2 to be used during auto-switching of CLKin_SEL_MODE. 0: Not enabled for auto mode 1: Enabled for auto mode 4 CLKin1_EN 1 Enable CLKin1 to be used during auto-switching of CLKin_SEL_MODE. 0: Not enabled for auto mode 1: Enabled for auto mode DESCRIPTION Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 75 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Table 40. Register 0x146 (continued) BIT NAME POR DEFAULT 3 CLKin0_EN 1 2 CLKin2_TYPE 0 1 CLKin1_TYPE 0 DESCRIPTION Enable CLKin0 to be used during auto-switching of CLKin_SEL_MODE. 0: Not enabled for auto mode 1: Enabled for auto mode 0: Bipolar 1: MOS 0 CLKin0_TYPE 0 There are two buffer types for CLKin0, 1, and 2: bipolar and CMOS. Bipolar is recommended for differential inputs such as LVDS or LVPECL. CMOS is recommended for DC-coupled single-ended inputs. When using bipolar, CLKinX and CLKinX* must be AC coupled. When using CMOS, CLKinX and CLKinX* may be AC or DC coupled if the input signal is differential. If the input signal is single-ended, the used input may be either AC or DC coupled, and the unused input must AC grounded (see Driving CLKin and OSCin Pins With a SingleEnded Source). 9.7.4.2 CLKin_SEL_POL, CLKin_SEL_MODE, CLKin1_OUT_MUX, CLKin0_OUT_MUX Table 41. Register 0x147 BIT NAME POR DEFAULT 7 CLKin_SEL_POL 0 DESCRIPTION Inverts the CLKin polarity for use in pin select mode. 0: Active high 1: Active low Sets the mode used in determining the reference for PLL1. 6:4 CLKin_SEL_MODE 3 Field Value CLKin Mode 0 (0x00) CLKin0 manual 1 (0x01) CLKin1 manual 2 (0x02) CLKin2 manual 3 (0x03) Pin select mode 4 (0x04) Auto mode 5 (0x05) Reserved 6 (0x06) Reserved 7 (0x07) Reserved Selects where the output of the CLKin1 buffer is directed. 3:2 CLKin1_OUT_MUX 2 Field Value CLKin1 Destination 0 (0x00) Fin 1 (0x01) Feedback mux (zero-delay mode) 2 (0x02) PLL1 3 (0x03) Off Selects where the output of the CLKin0 buffer is directed. 1:0 76 CLKin0_OUT_MUX 2 Submit Documentation Feedback Field Value CLKin0 Destination 0 (0x00) SYSREF mux 1 (0x01) Reserved 2 (0x02) PLL1 3 (0x03) Off Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.4.3 CLKin_SEL0_MUX, CLKin_SEL0_TYPE This register has CLKin_SEL0 controls. Table 42. Register 0x148 BIT NAME POR DEFAULT 7:6 NA 0 DESCRIPTION Reserved This set the output value of the CLKin_SEL0 pin. This register only applies if CLKin_SEL0_TYPE is set to an output mode 5:3 CLKin_SEL0_MUX 0 Field Value Output Format 0 (0x00) Logic low 1 (0x01) CLKin0 LOS 2 (0x02) CLKin0 selected 3 (0x03) DAC locked 4 (0x04) DAC low 5 (0x05) DAC high 6 (0x06) SPI readback 7 (0x07) Reserved This sets the I/O type of the CLKin_SEL0 pin. 2:0 CLKin_SEL0_TYPE 2 Field Value Configuration Function 0 (0x00) Input Input mode, see Input Clock Switching - Pin Select Mode for description of input mode. 1 (0x01) Input with pull-up resistor 2 (0x02) Input with pull-down resistor 3 (0x03) Output (push-pull) 4 (0x04) Output inverted (push-pull) 5 (0x05) Reserved 6 (0x06) Output (open drain) Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Output modes; the CLKin_SEL0_MUX register for description of outputs. Submit Documentation Feedback 77 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.4.4 SDIO_RDBK_TYPE, CLKin_SEL1_MUX, CLKin_SEL1_TYPE This register has CLKin_SEL1 controls and register readback SDIO pin type. Table 43. Register 0x149 BIT NAME POR DEFAULT 7 NA 0 Reserved 6 SDIO_RDBK_TYPE 1 Sets the SDIO pin to open drain when during SPI readback in 3-wire mode. 0: Output, push-pull 1: Output, open drain. DESCRIPTION This set the output value of the CLKin_SEL1 pin. This register only applies if CLKin_SEL1_TYPE is set to an output mode. Field Value 5:3 CLKin_SEL1_MUX 0 Output Format 0 (0x00) Logic low 1 (0x01) CLKin1 LOS 2 (0x02) CLKin1 selected 3 (0x03) DAC locked 4 (0x04) DAC low 5 (0x05) DAC high 6 (0x06) SPI readback 7 (0x07) Reserved This sets the I/O type of the CLKin_SEL1 pin. 2:0 78 CLKin_SEL1_TYPE 2 Submit Documentation Feedback Field Value Configuration 0 (0x00) Input 1 (0x01) Input with pull-up resistor 2 (0x02) Input with pull-down resistor 3 (0x03) Output (push-pull) 4 (0x04) Output inverted (push-pull) 5 (0x05) Reserved 6 (0x06) Output (open drain) Function Input mode, see Input Clock Switching - Pin Select Mode for description of input mode. Output modes; see the CLKin_SEL1_MUX register for description of outputs. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.5 RESET_MUX, RESET_TYPE This register contains control of the RESET pin. Table 44. Register 0x14A BIT NAME POR DEFAUL T 7:6 NA 0 DESCRIPTION Reserved This sets the output value of the RESET pin. This register only applies if RESET_TYPE is set to an output mode. Field Value 5:3 RESET_MUX 0 Output Format 0 (0x00) Logic low 1 (0x01) Reserved 2 (0x02) CLKin2 selected 3 (0x03) DAC locked 4 (0x04) DAC low 5 (0x05) DAC high 6 (0x06) SPI readback This sets the I/O type of the RESET pin. 2:0 RESET_TYPE 2 Field Value Configuration 0 (0x00) Input Function 1 (0x01) Input with pull-up resistor 2 (0x02) Input with pull-down resistor Reset mode Reset pin high = reset 3 (0x03) Output (push-pull) 4 (0x04) Output inverted (push-pull) 5 (0x05) Reserved 6 (0x06) Output (open drain) Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Output modes; see the RESET_MUX register for description of outputs. Submit Documentation Feedback 79 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.6 (0x14B - 0x152) Holdover 9.7.6.1 LOS_TIMEOUT, LOS_EN, TRACK_EN, HOLDOVER_FORCE, MAN_DAC_EN, MAN_DAC[9:8] This register contains the holdover functions. Table 45. Register 0x14B BIT NAME POR DEFAULT DESCRIPTION This controls the amount of time in which no activity on a CLKin forces a clock switch event. 7:6 5 LOS_TIMEOUT LOS_EN 0 Field Value Timeout 0 (0x00) 370 kHz (2.7 s) 1 (0x01) 2.1 MHz (480 ns) 2 (0x02) 8.8 MHz (115 ns) 3 (0x03) 22 MHz (45 ns) 0 Enables the LOS (loss-of-signal) timeout control. Valid only for MOS clock inputs. To ensure LOS is valid for AC-coupled inputs, no termination is allowed between CLKinX and CLKinX* pins unless DC-blocked. For example, 100- termination across CLKin0 and CLKin0* pins on the IC side of AC coupling capacitors would invalidate the LOS detector. If termination is required, it should be placed on the other side of the AC coupling capacitors, away from the IC pins. 0: Disabled 1: Enabled 1 Enable the DAC to track the PLL1 tuning voltage, optionally for use in holdover mode. After device reset, tracking starts at DAC code = 512 (midrange). Tracking can be used to monitor PLL1 voltage in any mode. 0: Disabled 1: Enabled, only tracks when PLL1 is locked. 4 TRACK_EN 3 HOLDOVER _FORCE 0 This bit forces holdover mode. When holdover mode is forced, if MAN_DAC_EN = 1, then the DAC sets the programmed MAN_DAC value. Otherwise the tracked DAC value sets the DAC voltage. 0: Disabled 1: Enabled 2 MAN_DAC_EN 1 This bit enables the manual DAC mode. 0: Automatic 1: Manual 1:0 MAN_DAC[9:8] 2 See MAN_DAC[9:8], MAN_DAC[7:0] for more information on the MAN_DAC settings. 80 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.6.2 MAN_DAC[9:8], MAN_DAC[7:0] These registers set the value of the DAC in holdover mode when used manually. Table 46. MAN_DAC[9:0] BIT REGISTERS 7:2 0x14B MSB LSB 0x14B[1:0] 0x14C[7:0] POR DEFAULT NAME DESCRIPTION See LOS_TIMEOUT, LOS_EN, TRACK_EN, HOLDOVER_FORCE, MAN_DAC_EN, MAN_DAC[9:8] for information on these bits. Sets the value of the manual DAC when in manual DAC mode. 1:0 7:0 0x14B 0x14C MAN_DAC[9:8] 2 MAN_DAC[7:0] 0 Field Value DAC Value 0 (0x00) 0 1 (0x01) 1 2 (0x02) 2 ... ... 1022 (0x3FE) 1022 1023 (0x3FF) 1023 9.7.6.3 DAC_TRIP_LOW This register contains the high value at which holdover mode is entered. Table 47. Register 0x14D BIT NAME POR DEFAULT 7:6 NA 0 DESCRIPTION Reserved Voltage from GND at which holdover is entered if HOLDOVER_VTUNE_DET is enabled. 5:0 DAC_TRIP_LOW 0 Field Value DAC Trip Value 0 (0x00) 1 x Vcc / 64 1 (0x01) 2 x Vcc / 64 2 (0x02) 3 x Vcc / 64 3 (0x03) 4 x Vcc / 64 ... ... 61 (0x17) 62 x Vcc / 64 62 (0x18) 63 x Vcc / 64 63 (0x19) 64 x Vcc / 64 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 81 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.6.4 DAC_CLK_MULT, DAC_TRIP_HIGH This register contains the multiplier for the DAC clock counter, and the low value at which holdover mode is entered. Table 48. Register 0x14E BIT NAME POR DEFAULT DESCRIPTION This is the multiplier for the DAC_CLK_CNTR which sets the rate at which the DAC value is tracked. Field Value 7:6 DAC_CLK_MULT 0 DAC Multiplier Value 0 (0x00) 4 1 (0x01) 64 2 (0x02) 1024 3 (0x03) 16384 Voltage from Vcc at which holdover is entered if HOLDOVER_VTUNE_DET is enabled. 5:0 DAC_TRIP_HIGH 9.7.6.5 0 Field Value DAC Trip Value 0 (0x00) 1 x Vcc / 64 1 (0x01) 2 x Vcc / 64 2 (0x02) 3 x Vcc / 64 3 (0x03) 4 x Vcc / 64 ... ... 61 (0x17) 62 x Vcc / 64 62 (0x18) 63 x Vcc / 64 63 (0x19) 64 x Vcc / 64 DAC_CLK_CNTR This register contains the value of the DAC when in tracked mode. Table 49. Register 0x14F BIT NAME POR DEFAULT DESCRIPTION This with DAC_CLK_MULT set the rate at which the DAC is updated. The update rate (in seconds) is = DAC_CLK_MULT * DAC_CLK_CNTR / PLL1 PDF (Hz) 7:0 82 DAC_CLK_CNTR 127 Submit Documentation Feedback Field Value DAC Value 0 (0x00) 0 1 (0x01) 1 2 (0x02) 2 3 (0x03) 3 ... ... 253 (0xFD) 253 254 (0xFE) 254 255 (0xFF) 255 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.6.6 CLKin_OVERRIDE, HOLDOVER_PLL1_DET, HOLDOVER_LOS_DET, HOLDOVER_VTUNE_DET, HOLDOVER_HITLESS_SWITCH, HOLDOVER_EN This register has controls for enabling clock in switch events. Table 50. Register 0x150 BIT NAME POR DEFAULT 7 NA 0 Reserved 6 CLKin _OVERRIDE 0 When CLKin_SEL_MODE = 0/1/2 to select a manual clock input, CLKin_OVERRIDE = 1 forces that clock input. Used with clock distribution mode for best performance. 0: Normal, no override. 1: Force select of only CLKin0/1/2, as specified by CLKin_SEL_MODE in manual mode. 5 NA 0 Reserved 4 HOLDOVER _PLL1_DET 0 This enables the HOLDOVER when PLL1 lock detect signal transitions from high to low. 0: PLL1 DLD does not cause a clock switch event 1: PLL1 DLD causes a clock switch event 3 HOLDOVER _LOS_DET 0 This enables HOLDOVER when PLL1 LOS signal is detected. 0: Disabled 1: Enabled 2 HOLDOVER _VTUNE_DET 0 Enables the DAC Vtune rail detections. When the DAC achieves a specified Vtune, if this bit is enabled, the current clock input is considered invalid and an input clock switch event is generated. 0: Disabled 1: Enabled 1 HOLDOVER _HITLESS _SWITCH 1 Determines whether a clock switch event will enter holdover use hitless switching. 0: Hard Switch 1: Hitless switching (has an undefined switch time) 0 HOLDOVER_EN 1 Sets whether holdover mode can be entered when holdover conditions are met. 0: Disabled 1: Enabled DESCRIPTION 9.7.6.7 HOLDOVER_DLD_CNT[13:8], HOLDOVER_DLD_CNT[7:0] Table 51. HOLDOVER_DLD_CNT[13:0] MSB LSB 0x151[5:0] 0x152[7:0] This register has the number of valid clocks of PLL1 PDF before holdover is exited. Table 52. Registers 0x151 and 0x152 BIT REGISTERS NAME POR DEFAULT 7:6 0x151 NA 0 DESCRIPTION Reserved The number of valid clocks of PLL1 PDF before holdover mode is exited. 5:0 7:0 0x151 0x152 HOLDOVER _DLD_CNT[13:8] HOLDOVER _DLD_CNT[7:0] 2 0 Field Value Count Value 0 (0x00) 0 1 (0x01) 1 2 (0x02) 2 ... ... 16382 (0x3FFE) 16382 16383 (0x3FFF) 16383 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 83 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.7 (0x153 - 0x15F) PLL1 Configuration 9.7.7.1 CLKin0_R[13:8], CLKin0_R[7:0] Table 53. CLKin0_R[13:0] MSB LSB 0x153[5:0] 0x154[7:0] These registers contain the value of the CLKin0 divider. BIT REGISTERS NAME POR DEFAULT 7:6 0x153 NA 0 DESCRIPTION Reserved The value of PLL1 R divider when CLKin0 is selected. 5:0 7:0 0x153 0x154 CLKin0_R[13:8] CLKin0_R[7:0] 0 120 Field Value Divide Value 0 (0x00) Reserved 1 (0x01) 1 2 (0x02) 2 ... ... 16382 (0x3FFE) 16382 16383 (0x3FFF) 16383 9.7.7.2 CLKin1_R[13:8], CLKin1_R[7:0] Table 54. CLKin1_R[13:0] MSB LSB 0x155[5:0] 0x156[7:0] These registers contain the value of the CLKin1 R divider. Table 55. Registers 0x155 and 0x156 BIT REGISTERS NAME POR DEFAULT 7:6 0x155 NA 0 DESCRIPTION Reserved The value of PLL1 R divider when CLKin1 is selected. 5:0 7:0 84 0x155 0x156 CLKin1_R[13:8] CLKin1_R[7:0] Submit Documentation Feedback 0 150 Field Value Divide Value 0 (0x00) Reserved 1 (0x01) 1 2 (0x02) 2 ... ... 16382 (0x3FFE) 16382 16383 (0x3FFF) 16383 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.7.3 CLKin2_R[13:8], CLKin2_R[7:0] MSB LSB 0x157[5:0] 0x158[7:0] These registers contain the value of the CLKin2 R divider. Table 56. Registers 0x157 and 0x158 BIT REGISTERS NAME POR DEFAULT 7:6 0x157 NA 0 DESCRIPTION Reserved The value of PLL1 R divider when CLKin2 is selected. 5:0 7:0 0x157 0x158 CLKin2_R[13:8] CLKin2_R[7:0] 0 150 Field Value Divide Value 0 (0x00) Reserved 1 (0x01) 1 2 (0x02) 2 ... ... 16382 (0x3FFE) 16382 16383 (0x3FFF) 16383 9.7.7.4 PLL1_N Table 57. PLL1_N[13:8], PLL1_N[7:0] PLL1_N[13:0] MSB LSB 0x159[5:0] 0x15A[7:0] These registers contain the N divider value for PLL1. Table 58. Registers 0x159 and 0x15A BIT REGISTERS NAME POR DEFAULT 7:6 0x159 NA 0 DESCRIPTION Reserved The value of PLL1 N divider. 5:0 7:0 0x159 0x15A PLL1_N[13:8] PLL1_N[7:0] 0 120 Field Value Divide Value 0 (0x00) Not valid 1 (0x01) 1 2 (0x02) 2 ... ... 16,383 (0x3FFF) 16,383 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 85 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.7.5 PLL1_WND_SIZE, PLL1_CP_TRI, PLL1_CP_POL, PLL1_CP_GAIN This register controls the PLL1 phase detector. Table 59. Register 0x15B BIT NAME POR DEFAULT DESCRIPTION PLL1_WND_SIZE sets the window size used for digital lock detect for PLL1. If the phase error between the reference and feedback of PLL1 is less than specified time, the PLL1 lock counter increments. 7:6 5 4 PLL1_WND_SIZE PLL1_CP_TRI PLL1_CP_POL 3 Field Value Definition 0 (0x00) 4 ns 1 (0x01) 9 ns 2 (0x02) 19 ns 3 (0x03) 43 ns 0 This bit allows for the PLL1 charge pump output pin, CPout1, to be placed into TRI-STATE. 0: PLL1 CPout1 is active 1: PLL1 CPout1 is at TRI-STATE 1 PLL1_CP_POL sets the charge pump polarity for PLL1. Many VCXOs use positive slope. A positive-slope VCXO increases output frequency with increasing voltage. A negativeslope VCXO decreases output frequency with increasing voltage. 0: Negative-slope VCO/VCXO 1: Positive-slope VCO/VCXO This bit programs the PLL1 charge pump output current level. 3:0 86 PLL1_CP_GAIN 4 Submit Documentation Feedback Field Value Gain 0 (0x00) 50 A 1 (0x01) 150 A 2 (0x02) 250 A 3 (0x03) 350 A 4 (0x04) 450 A ... ... 14 (0x0E) 1450 A 15 (0x0F) 1550 A Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.7.6 PLL1_DLD_CNT[13:8], PLL1_DLD_CNT[7:0] Table 60. PLL1_DLD_CNT[13:0] MSB LSB 0x15C[5:0] 0x15D[7:0] This register contains the value of the PLL1 DLD counter. Table 61. Registers 0x15C and 0x15D BIT REGISTERS NAME POR DEFAULT 7:6 0x15C NA 0 5:0 7:0 0x15C 0x15D DESCRIPTION Reserved The reference and feedback of PLL1 must be within the window of phase error, as specified by PLL1_WND_SIZE for this many phase detector cycles, before PLL1 digital lock detect is asserted. PLL1_DLD _CNT[13:8] 32 PLL1_DLD _CNT[7:0] 0 Field Value Delay Value 0 (0x00) Reserved 1 (0x01) 1 2 (0x02) 2 3 (0x03) 3 ... ... 16,382 (0x3FFE) 16,382 16,383 (0x3FFF) 16,383 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 87 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.7.7 PLL1_R_DLY, PLL1_N_DLY This register contains the delay value for PLL1 N and R delays. Table 62. Register 0x15E BIT NAME POR DEFAULT 7:6 NA 0 DESCRIPTION Reserved Increasing delay of PLL1_R_DLY causes the outputs to lag from CLKinX. For use in zerodelay mode. 5:3 PLL1_R_DLY 0 Field Value Gain 0 (0x00) 0 ps 1 (0x01) 205 ps 2 (0x02) 410 ps 3 (0x03) 615 ps 4 (0x04) 820 ps 5 (0x05) 1025 ps 6 (0x06) 1230 ps 7 (0x07) 1435 ps Increasing delay of PLL1_N_DLY causes the outputs to lead from CLKinX. For use in zerodelay mode. Field Value 2:0 88 PLL1_N_DLY 0 Submit Documentation Feedback Gain 0 (0x00) 0 ps 1 (0x01) 205 ps 2 (0x02) 410 ps 3 (0x03) 615 ps 4 (0x04) 820 ps 5 (0x05) 1025 ps 6 (0x06) 1230 ps 7 (0x07) 1435 ps Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.7.8 PLL1_LD_MUX, PLL1_LD_TYPE This register configures the PLL1 LD pin. Table 63. Register 0x15F BIT NAME POR DEFAULT DESCRIPTION This sets the output value of the Status_LD1 pin. Field Value 7:3 PLL1_LD_MUX 1 MUX Value 0 (0x00) Logic low 1 (0x01) PLL1 DLD 2 (0x02) PLL2 DLD 3 (0x03) PLL1 and PLL2 DLD 4 (0x04) Holdover status 5 (0x05) DAC locked 6 (0x06) Reserved 7 (0x07) SPI readback 8 (0x08) DAC rail 9 (0x09) DAC low 10 (0x0A) DAC high 11 (0x0B) PLL1_N 12 (0x0C) PLL1_N/2 13 (0x0D) PLL2_N 14 (0x0E) PLL2_N/2 15 (0x0F) PLL1_R 16 (0x10) PLL1_R/2 17 (0x11) PLL2_R (1) 18 (0x12) PLL2_R/2 (1) Sets the I/O type of the Status_LD1 pin. 2:0 (1) PLL1_LD_TYPE 6 Field Value TYPE 0 (0x00) Reserved 1 (0x01) Reserved 2 (0x02) Reserved 3 (0x03) Output (push-pull) 4 (0x04) Output inverted (push-pull) 5 (0x05) Reserved 6 (0x06) Output (open drain) Only valid when PLL2_LD_MUX is not set to 2 (PLL2_DLD) or 3 (PLL1 and PLL2 DLD). Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 89 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.8 (0x160 - 0x16E) PLL2 Configuration 9.7.8.1 PLL2_R[11:8], PLL2_R[7:0] Table 64. PLL2_R[11:0] MSB LSB 0x160[3:0] 0x161[7:0] This register contains the value of the PLL2 R divider. Table 65. Registers 0x160 and 0x161 BIT REGISTERS NAME POR DEFAULT 7:4 0x160 NA 0 DESCRIPTION Reserved Valid values for the PLL2 R divider. 3:0 7:0 90 0x160 0x161 PLL2_R[11:8] PLL2_R[7:0] Submit Documentation Feedback 0 2 Field Value Divide Value 0 (0x00) Not valid 1 (0x01) 1 2 (0x02) 2 3 (0x03) 3 ... ... 4,094 (0xFFE) 4,094 4,095 (0xFFF) 4,095 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.8.2 PLL2_P, OSCin_FREQ, PLL2_XTAL_EN, PLL2_REF_2X_EN This register sets other PLL2 functions. Table 66. Register 0x162 BIT NAME POR DEFAULT DESCRIPTION The PLL2 N prescaler divides the output of the VCO as selected by Mode_MUX1 and is connected to the PLL2 N divider. 7:5 PLL2_P 2 Field Value Value 0 (0x00) 8 1 (0x01) 2 2 (0x02) 2 3 (0x03) 3 4 (0x04) 4 5 (0x05) 5 6 (0x06) 6 7 (0x07) 7 The frequency of the PLL2 reference input to the PLL2 phase detector (OSCin/OSCin* port) must be programmed to support proper operation of the frequency calibration routine, which locks the internal VCO to the target frequency. Field Value 4:2 1 0 OSCin_FREQ PLL2_XTAL_EN PLL2_REF_2X_EN 7 OSCin Frequency 0 (0x00) 0 to 63 MHz 1 (0x01) >63 MHz to 127 MHz 2 (0x02) >127 MHz to 255 MHz 3 (0x03) Reserved 4 (0x04) >255 MHz to 500 MHz 5 (0x05) to 7(0x07) Reserved 0 If an external crystal is being used to implement a discrete VCXO, the internal feedback amplifier must be enabled with this bit to complete the oscillator circuit. 0: Oscillator amplifier disabled 1: Oscillator amplifier enabled 1 Enabling the PLL2 reference frequency doubler allows for higher phase-detector frequencies on PLL2 than would normally be allowed with the given VCXO or crystal frequency. Higher phase-detector frequencies reduce the PLL N values, which makes the design of wider-loop bandwidth filters possible. 0: Doubler disabled 1: Doubler enabled Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 91 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.8.3 www.ti.com PLL2_N_CAL PLL2_N_CAL[17:0] PLL2 never uses zero-delay during frequency calibration. These registers contain the value of the PLL2 N divider used with the PLL2 prescaler during calibration for cascaded zero-delay mode. When calibration is complete, PLL2 uses the PLL2_N value. Cascaded zero-delay mode occurs when PLL2_NCLK_MUX = 1. Table 67. Register 0x162 MSB -- LSB 0x163[1:0] 0x164[7:0] 0x165[7:0] Table 68. Registers 0x163, 0x164, and 0x165 BIT REGISTERS NAME POR DEFAULT 7:2 0x163 NA 0 1:0 0x163 PLL2_N _CAL[17:16] 0 7:0 7:0 0x164 PLL2_N_CAL[15:8] 0x165 PLL2_N_CAL[7:0] DESCRIPTION Reserved 0 12 Field Value Divide Value 0 (0x00) Not valid 1 (0x01) 1 2 (0x02) 2 ... ... 262,143 (0x3FFFF) 262,143 9.7.8.4 PLL2_FCAL_DIS, PLL2_N This register disables frequency calibration and sets the PLL2 N divider value. Programming register 0x168 starts a VCO calibration routine if PLL2_FCAL_DIS = 0. Table 69. PLL2_N[17:0] MSB -- LSB 0x166[1:0] 0x167[7:0] 0x168[7:0] Table 70. Registers 0x166, 0x167, and 0x168 BIT REGISTERS NAME POR DEFAULT 7:3 0x166 NA 0 Reserved 2 0x166 PLL2_FCAL_DIS 0 This disables the PLL2 frequency calibration on programming register 0x168. 0: Frequency calibration enabled 1: Frequency calibration disabled 1:0 0x166 PLL2_N[17:16] 0 7:0 7:0 92 0x167 0x168 PLL2_N[15:8] PLL2_N[7:0] Submit Documentation Feedback 0 12 DESCRIPTION Field Value Divide Value 0 (0x00) Not valid 1 (0x01) 1 2 (0x02) 2 ... ... 262,143 (0x3FFFF) 262,143 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.8.5 PLL2_WND_SIZE, PLL2_CP_GAIN, PLL2_CP_POL, PLL2_CP_TRI This register controls the PLL2 phase detector. Table 71. Register 0x169 BIT NAME POR DEFAULT 7 NA 0 DESCRIPTION Reserved PLL2_WND_SIZE sets the window size used for digital lock detect for PLL2. If the phase error between the reference and feedback of PLL2 is less than the specified time, then the PLL2 lock counter increments. This value must be programmed to 2 (3.7 ns). 6:5 PLL2_WND_SIZE 2 Field Value Definition 0 (0x00) Reserved 1 (0x01) Reserved 2 (0x02) 3.7 ns 3 (0x03) Reserved This bit programs the PLL2 charge pump output current level. The table below also illustrates the impact of the PLL2 TRISTATE bit in conjunction with PLL2_CP_GAIN. 4:3 2 PLL2_CP_GAIN PLL2_CP_POL 3 0 Field Value Definition 0 (0x00) 100 A 1 (0x01) 400 A 2 (0x02) 1600 A 3 (0x03) 3200 A PLL2_CP_POL sets the charge pump polarity for PLL2. The internal VCO requires the negative charge pump polarity to be selected. Many VCOs use positive slope. A positive-slope VCO increases output frequency with increasing voltage. A negative-slope VCO decreases output frequency with increasing voltage. Field Value Description 0 Negative-slope VCO/VCXO 1 Positive-slope VCO/VCXO 1 PLL2_CP_TRI 0 PLL2_CP_TRI TRI-STATEs the output of the PLL2 charge pump. 0: Disabled 1: TRI-STATE 0 Fixed Value 1 When programming register 0x169, this field must be set to 1. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 93 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.8.6 www.ti.com SYSREF_REQ_EN, PLL2_DLD_CNT Table 72. PLL2_DLD_CNT[15:0] MSB LSB 0x16A[5:0] 0x16B[7:0] This register has the value of the PLL2 DLD counter. Table 73. Registers 0x16A and 0x16B BIT REGISTERS NAME POR DEFAULT 7 0x16A NA 0 Reserved 6 0x16A SYSREF_REQ_EN 0 Enables the SYNC/SYSREF_REQ pin to force the SYSREF_MUX = 3 for continuous pulses. When using this feature, enable the pulser and set SYSREF_MUX = 2 (pulser). 5:0 7:0 94 0x16A 0x16B PLL2_DLD _CNT[13:8] PLL2_DLD_CNT Submit Documentation Feedback DESCRIPTION The reference and feedback of PLL2 must be within the window of phase error, as specified by PLL2_WND_SIZE for PLL2_DLD_CNT cycles, before PLL2 digital lock detect is asserted. 32 0 Field Value Divide Value 0 (0x00) Not valid 1 (0x01) 1 2 (0x02) 2 3 (0x03) 3 ... ... 16,382 (0x3FFE) 16,382 16,383 (0x3FFF) 16,383 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.8.7 PLL2_LF_R4, PLL2_LF_R3 This register controls the integrated loop filter resistors. Table 74. Register 0x16C BIT NAME POR DEFAULT 7:6 NA 0 DESCRIPTION Reserved Internal loop filter components are available for PLL2, enabling either 3rd- or 4th-order loop filters without requiring external components. Internal loop filter resistor R4 can be set according to the following table. 5:3 PLL2_LF_R4 0 Field Value Resistance 0 (0x00) 200 1 (0x01) 1 k 2 (0x02) 2 k 3 (0x03) 4 k 4 (0x04) 16 k 5 (0x05) Reserved 6 (0x06) Reserved 7 (0x07) Reserved Internal loop filter components are available for PLL2, enabling either 3rd- or 4th-order loop filters without requiring external components. Internal loop filter resistor R3 can be set according to the following table. 2:0 PLL2_LF_R3 0 Field Value Resistance 0 (0x00) 200 1 (0x01) 1 k 2 (0x02) 2 k 3 (0x03) 4 k 4 (0x04) 16 k 5 (0x05) Reserved 6 (0x06) Reserved 7 (0x07) Reserved Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 95 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.8.8 PLL2_LF_C4, PLL2_LF_C3 This register controls the integrated loop filter capacitors. Table 75. Register 0x16D BIT NAME POR DEFAULT DESCRIPTION Internal loop filter components are available for PLL2, enabling either 3rd- or 4th-order loop filters without requiring external components. Internal loop filter capacitor C4 can be set according to the following table. 7:4 PLL2_LF_C4 0 Field Value Capacitance 0 (0x00) 10 pF 1 (0x01) 15 pF 2 (0x02) 29 pF 3 (0x03) 34 pF 4 (0x04) 47 pF 5 (0x05) 52 pF 6 (0x06) 66 pF 7 (0x07) 71 pF 8 (0x08) 103 pF 9 (0x09) 108 pF 10 (0x0A) 122 pF 11 (0x0B) 126 pF 12 (0x0C) 141 pF 13 (0x0D) 146 pF 14 (0x0E) Reserved 15 (0x0F) Reserved Internal loop filter components are available for PLL2, enabling either 3rd- or 4th-order loop filters without requiring external components. Internal loop filter capacitor C3 can be set according to the following table. 3:0 96 PLL2_LF_C3 0 Submit Documentation Feedback Field Value Capacitance 0 (0x00) 10 pF 1 (0x01) 11 pF 2 (0x02) 15 pF 3 (0x03) 16 pF 4 (0x04) 19 pF 5 (0x05) 20 pF 6 (0x06) 24 pF 7 (0x07) 25 pF 8 (0x08) 29 pF 9 (0x09) 30 pF 10 (0x0A) 33 pF 11 (0x0B) 34 pF 12 (0x0C) 38 pF 13 (0x0D) 39 pF 14 (0x0E) Reserved 15 (0x0F) Reserved Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.8.9 PLL2_LD_MUX, PLL2_LD_TYPE This register sets the output value of the Status_LD2 pin. Table 76. Register 0x16E BIT NAME POR DEFAULT DESCRIPTION This sets the output value of the Status_LD2 pin. Field Value 7:3 PLL2_LD_MUX 2 MUX Value 0 (0x00) Logic low 1 (0x01) PLL1 DLD 2 (0x02) PLL2 DLD 3 (0x03) PLL1 and PLL2 DLD 4 (0x04) Holdover status 5 (0x05) DAC locked 6 (0x06) Reserved 7 (0x07) SPI readback 8 (0x08) DAC rail 9 (0x09) DAC low 10 (0x0A) DAC high 11 (0x0B) PLL1_N 12 (0x0C) PLL1_N/2 13 (0x0D) PLL2_N 14 (0x0E) PLL2_N/2 15 (0x0F) PLL1_R 16 (0x10) PLL1_R/2 17 (0x11) PLL2_R (1) 18 (0x12) PLL2_R/2 (1) Sets the I/O type of the Status_LD2 pin. 2:0 (1) PLL2_LD_TYPE 6 Field Value TYPE 0 (0x00) Reserved 1 (0x01) Reserved 2 (0x02) Reserved 3 (0x03) Output (push-pull) 4 (0x04) Output inverted (push-pull) 5 (0x05) Reserved 6 (0x06) Output (open drain) Only valid when PLL1_LD_MUX is not set to 2 (PLL2_DLD) or 3 (PLL1 and PLL2 DLD). Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 97 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.9 (0x16F - 0x1FFF) Misc Registers 9.7.9.1 PLL2_PRE_PD, PLL2_PD Table 77. Register 0x173 BIT NAME 7 N/A 6 PLL2_PRE_PD 5 PLL2_PD 4:0 N/A DESCRIPTION Reserved Powerdown PLL2 prescaler 0: Normal operation 1: Powerdown Powerdown PLL2 0: Normal operation 1: Powerdown Reserved 9.7.9.2 VCO1_DIV Sets the VCO1 VCO divider value. This divider cannot be bypassed, and has a minimum value of 2. This register is reserved for LMK04826 and LMK04828, and should be left unprogrammed. Table 78. Register 0x174 BIT NAME POR DEFAULT 7:5 N/A 0 DESCRIPTION Reserved When VCO_MUX selects VCO1 for LMK04821, the clock distribution frequency is equal to VCO1 frequency divided by this divide value. This divider is also on the PLL2 feedback path, and impacts the PLL2 N divider value. Unlisted field values are reserved. 4:0 VCO1_DIV (LMK04821 only) 0 Field Value Divide Value 0 (0x00) 2 5 (0x05) 3 10 (0x0A) 8 20 (0x14) 4 23 (0x17) 5 27 (0x1B) 7 30 (0x1E) 6 9.7.9.3 OPT_REG_1 This register must be written with the following value, depending on which LMK0482x family part is used to optimize VCO1 phase-noise performance over temperature. This register must be written before writing register 0x168 when using VCO1. Table 79. Register 0x17C BIT NAME 7:0 OPT_REG_1 98 DESCRIPTION 21: LMK04821 24: LMK04826 21: LMK04828 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.9.4 OPT_REG_2 This register must be written with the following value, depending on which LMK0482x family part is used to optimize VCO1 phase-noise performance over temperature. This register must be written before writing register 0x168 when using VCO1. Table 80. Register 0x17D BIT 7:0 NAME OPT_REG_2 DESCRIPTION 51: LMK04821 119: LMK04826 51: LMK04828 9.7.9.5 RB_PLL1_LD_LOST, RB_PLL1_LD, CLR_PLL1_LD_LOST Table 81. Register 0x182 BIT NAME 7:3 N/A 2 RB_PLL1_LD_LOST 1 RB_PLL1_LD 0 CLR_PLL1_LD_LOST DESCRIPTION Reserved This is set when PLL1 DLD edge falls. Does not set if cleared while PLL1 DLD is low. Read back 0: PLL1 DLD is low. Read back 1: PLL1 DLD is high. To reset RB_PLL1_LD_LOST, write CLR_PLL1_LD_LOST with 1 and then 0. 0: RB_PLL1_LD_LOST is set on next falling PLL1 DLD edge. 1: RB_PLL1_LD_LOST is held clear (0). User must clear this bit to allow RB_PLL1_LD_LOST to become set again. 9.7.9.6 RB_PLL2_LD_LOST, RB_PLL2_LD, CLR_PLL2_LD_LOST Table 82. Register 0x0x183 BIT NAME 7:3 N/A 2 RB_PLL2_LD_LOST 1 RB_PLL2_LD PLL1_LD_MUX or PLL2_LD_MUX must select setting 2 (PLL2 DLD) for valid reading of this bit. Read back 0: PLL2 DLD is low. Read back 1: PLL2 DLD is high. CLR_PLL2_LD_LOST To reset RB_PLL2_LD_LOST, write CLR_PLL2_LD_LOST with 1 and then 0. 0: RB_PLL2_LD_LOST is set on next falling PLL2 DLD edge. 1: RB_PLL2_LD_LOST is held clear (0). User must clear this bit to allow RB_PLL2_LD_LOST to become set again. 0 DESCRIPTION Reserved This is set when PLL2 DLD edge falls. Does not set if cleared while PLL2 DLD is low. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 99 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 9.7.9.7 RB_DAC_VALUE(MSB), RB_CLKinX_SEL, RB_CLKinX_LOS This register provides read back access to CLKinX selection indicator and CLKinX LOS indicator. The 2 MSBs are shared with the RB_DAC_VALUE. See RB_DAC_VALUE section. Table 83. Register 0x184 BIT NAME DESCRIPTION 7:6 RB_DAC_VALUE[9:8] 5 RB_CLKin2_SEL Read back 0: CLKin2 is not selected for input to PLL1. Read back 1: CLKin2 is selected for input to PLL1. 4 RB_CLKin1_SEL Read back 0: CLKin1 is not selected for input to PLL1. Read back 1: CLKin1 is selected for input to PLL1. 3 RB_CLKin0_SEL Read back 0: CLKin0 is not selected for input to PLL1. Read back 1: CLKin0 is selected for input to PLL1. 2 N/A 1 RB_CLKin1_LOS Read back 1: CLKin1 LOS is active. Read back 0: CLKin1 LOS is not active. 0 RB_CLKin0_LOS Read back 1: CLKin0 LOS is active. Read back 0: CLKin0 LOS is not active. See RB_DAC_VALUE section. 9.7.9.8 RB_DAC_VALUE Contains the value of the DAC for user readback. FIELD NAME RB_DAC_VALUE MSB LSB 0x184 [7:6] 0x185 [7:0] Table 84. Registers 0x184 and 0x185 BIT REGISTERS NAME POR DEFAULT 7:6 0x184 RB_DAC_ VALUE[9:8] 2 7:0 0x185 RB_DAC_ VALUE[7:0] 0 DESCRIPTION DAC value is 512 on power-on reset; if PLL1 locks upon power-up, the DAC value changes. 9.7.9.9 RB_HOLDOVER Table 85. Register 0x188 BIT NAME 7:5 N/A 4 RB_HOLDOVER 3:0 N/A 100 DESCRIPTION Reserved Read back 0: Not in HOLDOVER Read back 1: In HOLDOVER Reserved Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 9.7.9.10 SPI_LOCK Prevents SPI registers from being written to, except for 0x1FFD, 0x1FFE, and 0x1FFF. These registers must be written to sequentially and in order: 0x1FFD, 0x1FFE, 0x1FFF. These registers cannot be read back. MSB -- LSB 0x1FFD [7:0] 0x1FFE [7:0] 0x1FFF [7:0] Table 86. Registers 0x1FFD, 0x1FFE, and 0x1FFF BIT REGISTERS NAME POR DEFAULT 7:0 0x1FFD SPI_LOCK[23:16] 0 0: Registers unlocked. 1 to 255: Registers locked 7:0 0x1FFE SPI_LOCK[15:8] 0 0: Registers unlocked. 1 to 255: Registers locked 7:0 0x1FFF SPI_LOCK[7:0] 83 0 to 82: Registers locked 83: Registers unlocked 84 to 256: Registers locked DESCRIPTION Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 101 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 10 Applications and Implementation 10.1 Application Information To assist customers in frequency planning and designing loop filters, Texas Instruments provides PLLatinum Sim (www.ti.com/tool/PLLATINUMSIM-SW) and TICS Pro (www.ti.com/tool/TICSPRO-SW). 10.2 Digital Lock Detect Frequency Accuracy The digital lock detect circuit is used to determine PLL1 locked, PLL2 locked, and holdover exit events. A window size and lock count register are programmed to set a ppm frequency accuracy of reference to feedback signals of the PLL, for each event to occur. When a PLL digital lock event occurs, the PLL digital lock detect is asserted true. When the holdover exit event occurs, the device exits holdover mode. EVENT PLL WINDOW SIZE LOCK COUNT PLL1 locked PLL1 PLL1_WND_SIZE PLL1_DLD_CNT PLL2 locked PLL2 PLL2_WND_SIZE PLL2_DLD_CNT Holdover exit PLL1 PLL1_WND_SIZE HOLDOVER_DLD_CNT For a digital lock detect event to occur, there must be a "lock count" number of phase-detector cycles of PLLX, during which the time/phase error of the PLLX_R reference and PLLX_N feedback signal edges are within the user programmable "window size." Because there must be at least "lock count" phase-detector events before a lock event occurs, a minimum digital lock event time can be calculated as "lock count" / fPDX, where X = 1 for PLL1 or 2 for PLL2. By using Equation 6, values for a "lock count" and "window size" can be chosen to set the frequency accuracy required by the system in ppm before the digital lock detect event occurs: ppm = 1e6 x PLLX_WND_SIZE x fPDX PLLX_DLD_CNT (6) The effect of the "lock count" value is that it shortens the effective lock window size by dividing the "window size" by "lock count". If at any time the PLLX_R reference and PLLX_N feedback signals are outside the time window set by "window size", then the "lock count" value is reset to 0. 10.2.1 Minimum Lock Time Calculation Example To calculate the minimum PLL2 digital lock time given a PLL2 phase-detector frequency of 40 MHz and PLL2_DLD_CNT = 10,000: the minimum lock time of PLL2 is 10,000 / 40 MHz = 250 s. 102 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 10.3 Driving CLKin and OSCin Inputs 10.3.1 Driving CLKin and OSCin Pins With a Differential Source Both CLKin ports can be driven by differential signals. TI recommends that the CLKin input mode be set to bipolar (CLKinX_TYPE = 0) when using differential reference clocks. The OSCin input mode is hard-wired to bipolar-equivalent. The LMK0482x family internally biases the input pins, thus the differential interface should be AC coupled. The recommended circuits for driving the CLKin/OSCin pins with either LVDS or LVPECL are shown in Figure 24 and Figure 25. Figure 24. CLKinX and OSCin Termination for an LVDS Reference Clock Source Figure 25. CLKinX and OSCin Termination for an LVPECL Reference Clock Source A reference clock source that produces a differential sine wave output can drive the CLKin/OSCin pins using the following circuit. The signal level must conform to the requirements for the CLKin/OSCin pins listed in Electrical Characteristics. Figure 26. CLKinX and OSCin Termination for a Differential Sinewave Reference Clock Source Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 103 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Driving CLKin and OSCin Inputs (continued) 10.3.2 Driving CLKin and OSCin Pins With a Single-Ended Source The CLKin/OSCin pins of the LMK0482x family can be driven using a single-ended reference clock source; for example, either a sine wave source or an LVCMOS/LVTTL source. For the CLKin pins, either AC coupling or DC coupling may be used. For the OSCin pins, AC coupling is required. In the case of the sine wave source that is expecting a 50- load, TI recommends using AC coupling, as shown in the circuit below with a 50- termination. NOTE The signal level must conform to the requirements for the CLKin/OSCin pins listed in Electrical Characteristics. CLKinX_TYPE is recommended to be set to bipolar mode (CLKinX_TYPE = 0). OSCin is hard-wired to bipolar mode. Figure 27. CLKinX and OSCin Single-Ended Termination If the CLKin pins are being driven with a single-ended LVCMOS/LVTTL source, either DC coupling or AC coupling may be used. If DC coupling is used, the CLKinX_TYPE should be set to MOS buffer mode (CLKinX_TYPE = 1), and the voltage swing of the source must meet the specifications for DC-coupled, MOSmode clock inputs given in Electrical Characteristics. If AC coupling is used, the CLKinX_TYPE should be set to the bipolar buffer mode (CLKinX_TYPE = 0), and the voltage swing at the input pins must meet the specifications for AC-coupled, bipolar-mode clock inputs given in Electrical Characteristics. In AC-coupled bipolar mode, some attenuation of the clock input level may be required. A simple resistive divider circuit before the AC coupling capacitor is sufficient. Figure 28. DC-Coupled LVCMOS/LVTTL Reference Clock 104 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 10.4 Output Termination and Biasing 10.4.1 LVPECL Figure 29 shows the recommended resistor biasing configuration for the LVPECL format for both CLKout and OSCout pins. The LVPECL emitter resistors for DCLKoutX or SDCLKoutY can be selected such that 120 Re 240 . When OSCout (pins 40 and 41) are configured to provide a buffered oscillator output in LVPECL format, TI recommends setting the value of the emitter resistors for OSCout to 240 . To avoid bias mismatch or excessive loading of the bias circuitry, TI recommends connecting LVPECL outputs to the load through ACcoupling capacitors as shown. Figure 29. LVPECL Biasing for CLKout and OSCout 10.4.2 LVDS/HSDS Figure 30 shows the recommended resistor biasing configuration for the LVDS/HSDS format for both CLKout and OSCout pins. When connecting an HSDS output to a load, it should be AC-coupled. In cases where the common mode output voltage of the LMK0482x family LVDS matches the common mode input voltage of the LVDS receiver, DC coupling can be used; however, frequently LVDS is also AC-coupled to avoid any driver/receiver mismatch issues. The LVDS/HSDS driver requires a DC path for current from CLKoutX to CLKoutX* and from OSCout to OSCout* on initial startup. If a DC path for current is not present on startup, LVDS/HSDS outputs may start up with lower amplitude than expected, and in some cases could generate runt pulses or fail to oscillate for some time after startup. Whenever AC-coupled LVDS or HSDS is used with external termination, the 100- termination should be placed on the LMK0482x side of the AC-coupling capacitors as illustrated in Figure 30. Figure 30. LVDS/HSDS Output Termination for OSCout and CLKout, External Receiver Termination In cases where the termination is internal to the receiver, place 560 close to the CLKoutX/X* or OSCout/OSCout* pins, to provide a DC path for the output on startup as illustrated in Figure 31. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 105 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Output Termination and Biasing (continued) Figure 31. LVDS/HSDS Output Termination for OSCout and CLKout, Internal Receiver Termination 106 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 10.5 Typical Applications 10.5.1 Design Example This design example below highlights using the available tools to design loop filters and create a programming map for the LMK0482x. 10.5.1.1 Design Requirements Clocks outputs: * 1x 245.76-MHz clock for JESD204B ADC, LVPECL. - This clock requires the best performance in this example. * 2x 983.04-MHz clock for JESD204B DAC, LVPECL. * 1x 122.88-MHz clock for JESD204B FPGA block, LVDS * 4x 10.24-MHz SYSREF for ADC (LCPECL), DAC (LVPECL), FPGA (LVDS). * 2x 122.88-MHz clock for FPGA, LVDS For best performance, the highest possible phase detector frequency is used at PLL2. As such, a 122.88-MHz VCXO is used. 10.5.1.2 Detailed Design Procedure This information is current as of the date of the release of this data sheet. Design tools receive continuous improvements to add features and improve model accuracy. Refer to the software instructions or training for the latest features. 10.5.1.2.1 Device Configuration and Simulation - PLLatinum Sim Select the LMK04828 and choose the PLL and VCO to simulate. Make adjustments for more accurate simulations depending on the application. For example: * Enter the VCO gain of the external VCXO or possible external VCO-used device. * Adjust the charge pump current to help with loop filter component selection. Lower charge pump currents result in smaller components, but may increase impacts of leakage, and at the lowest values reduce PLL phase-noise performance. * PLLatinum Sim allows loading a custom phase noise plot for any block. Typically, a custom phase-noise plot is entered for CLKin to match the reference phase noise to device; a phase-noise plot for the VCXO can additionally be provided to match the performance of VCXO used. For improved accuracy in simulation and optimum loop filter design, load these custom noise profiles for use in the application. * The design tools return with high reference and phase-detector frequencies by default. If desired, experiment with different reference divider settings, phase detector frequencies, and loop bandwidths. Due to the narrow loop bandwidth used on PLL1, it is common to reduce the phase detector frequency on PLL1. 10.5.1.2.2 Device Programming Using the PLLatinum Sim configuration, the TICS Pro software is manually updated with this information to meet the required application. For the JESD204B outputs, place the device clocks on the DCLKoutX output, then turn on the paired SDCLKoutY output for SYSREF output. For non-JESD204B outputs, both DCLKoutX and paired SDCLKoutY may be driven by the device clock divider to maximize number of available outputs. Frequency planning for assignment of outputs: * To minimize crosstalk, perform frequency planning / CLKout assignments to keep common frequencies on outputs close together. * It is best to place common device clock output frequencies on outputs sharing the same Vcc group. For example, these outputs share Vcc4_CG2. Refer to Pin Configuration and Functions to see the Vcc groupings the clock outputs. In this example, the 245.76-MHz ADC output requires the best performance. DCLKout2 on the LMK0482x provides the best noise floor / performance. The 245.76 MHz is placed on DCLKout2 with 10.24-MHz SYSREF on SDCLKout3. * For best performance, the input and output drive level bits may be set. Best noise floor performance is achieved with CLKout2_IDL = 1 and CLKout2_ODL = 1. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 107 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Typical Applications (continued) In this example, the 983.04-MHz DAC output is placed on DCLKout4 and DCLKout6, with 10.24-MHz SYSREF on paired SDCLKout5 and SDCLKout7 outputs. * These outputs share Vcc4_CG2. In this example, the 122.88-MHz FPGA JESD204B output is placed on DCLKout10, with 10.24-MHz SYSREF on paired SDCLKout11 output. Additionally, the 122.88-MHz FPGA non-JESD204B outputs are placed on DCLKout8 and SDCLKout9. * When frequency planning, consider PLL2 as a clock output at the phase-detector frequency. As such, these 122.88-MHz outputs have been placed on the outputs close to the PLL2 and charge pump power supplies. The register programming can be validated live on the device, with a SPI header wired to a TI USB2ANY programmer. When the device programming is completed as desired in the TICS Pro software, it is possible to export the register settings by using the Export Hex Registers option in the file menu. 10.5.1.3 Application Curves Figure 32. DCLKout0, 245.76-MHz LVPECL20 With 240- Emitter Resistors CLKout0_1_IDL = 1, CLKout0_1_ODL = 1 108 Submit Documentation Feedback Figure 33. DCLKout2, 245.76-MHz LVPECL20 With 240- Emitter Resistors CLKout2_3_IDL = 1, CLKout2_3_ODL = 1 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Typical Applications (continued) Figure 34. DCLKout4, 983.04-MHz LVPECL16 With 240- Emitter Resistors CLKout4_5_IDL = 1, CLKout4_5_ODL = 0 Figure 35. DCLKout6, 983.04-MHz LVPECL16 With 240- Emitter Resistors CLKout6_7_IDL = 1, CLKout6_7_ODL = 0 Figure 36. DCLKout10, 122.88 MHz, LVDS CLKout10_11_IDL = 1, CLKout10_11_ODL = 0 Figure 37. SDCLKout11, 122.88 MHz, LVDS CLKout10_11_IDL = 1, CLKout10_11_ODL = 0 Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 109 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com Typical Applications (continued) Figure 38. OSCout, 122.88 MHz, LVCMOS (Norm/Inv) Normal Output Measured, Inverse 50- Termination Figure 39. Direct VCXO Measurement Open Loop, Holdover Mode Set 10.6 System Examples 10.6.1 System Level Diagram Figure 40 and Figure 41 show an LMK0482x family device with external circuitry for clocking and for power supply to serve as a guideline for good practices when designing with the LMK0482x family. Refer to Pin Connection Recommendations for more details on the pin connections and bypassing recommendations. Also refer to the evaluation board in LMK04826/28 User's Guide. PCB design will also play a role in device performance. 110 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 System Examples (continued) Figure 40. Example Application - System Schematic Except for Power Figure 40 shows the primary reference clock input is at CLKin0/0*. A secondary reference clock is driving CLKin1/1*. Both clocks are depicted as AC-coupled drivers. The VCXO attached to the OSCin/OSCin* port is configured as an AC-coupled single-ended driver. Any of the input ports (CLKin0/0*, CLKin1/1*, CLKin2/2*, OSCin/OSCin*) may be configured as either differential or single-ended (see Driving CLKin and OSCin Inputs). Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 111 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com System Examples (continued) The loop filter for PLL1 is configured as a 2nd-order passive filter, while the loop filter for PLL2 is configured as a 4th order passive filter (using internal 3rd and 4th order components). Typically it is not necessary to increase the filter beyond 2nd order for PLL1. PLL2 allows software programmability of the 3rd and 4th order components (see PLL2 Integrated Loop Filter Poles). PLLatinum Sim can be used to compute the loop filter values for optimal phase noise. All the LVPECL clock outputs are AC-coupled with 0.1 F capacitors. Some LVPECL outputs are depicted with 240- emitter resistors, and some are depicted with 150- emitter resistors. LVPECL clock outputs can use emitter resistors between 120 and 240 . OSCout LVPECL format only supports 240- emitter resistors is depicted with 240- emitter resistors. The LCPECL SYSREF output is DC-coupled, with termination values matching the conditions specified for LCPECL in the Electrical Characteristics. The non-JESD204B LVDS outputs are AC-coupled, and include 560 between the pins of the differential pair to create a DC path for current on startup (see LVDS/HSDS). The JESD204B LVDS outputs are DC-coupled. Unused outputs are left floating. PCB design will influence crosstalk performance. Tightly coupled clock traces will have less crosstalk than loosely coupled clock traces. Proximity to other clock traces will influence crosstalk. Figure 41. Example Application - Power System Schematic 112 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 System Examples (continued) Figure 41 shows an example decoupling and bypassing scheme for the LMK0482x, which could apply to the configuration shown in Figure 40. Components drawn in dotted lines are optional (see Pin Connection Recommendations). Two power planes are used in these example designs, one for the clock outputs and one for the PLL circuits. It is possible to reduce the number of decoupling components by tying together clock output Vcc pins for CLKouts that share the same frequency or otherwise can tolerate potential crosstalk between outputs with different frequencies. In the two examples, Vcc2 and Vcc11 can be tied together since no outputs are utilized from Clock Group 0. PCB design will influence impedance to the supply. Vias and traces will increase the impedance to the power supply. Ensure good direct return current paths. 10.7 Do's and Don'ts * * * * * * VCC Pins and Decoupling: all VCC pins must always be connected. Unused Clock Outputs: leave unused clock outputs floating and powered down. Unused Clock Inputs: unused clock inputs can be left floating. OSCout: When set to an LVPECL drive format, OSCout emitter resistors should be 240 to GND. Otherwise, OSCout may be treated like any other clock output. LVDS/HSDS Outputs: Ensure that there is a DC path for current from CLKoutX to CLKoutX*, and from OSCout to OSCout*, for all LVDS/HSDS outputs at startup. See LVDS/HSDS. RESET Pin: If the RESET pin is used, place a capacitor on RESET pin to prevent external noise from causing device reset. If reset functionality is not used, consider resetting GPIO as output to prevent external noise from causing device reset. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 113 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 11 Power Supply Recommendations 11.1 Pin Connection Recommendations 11.1.1 VCC Pins and Decoupling All Vcc pins must always be connected. Integrated capacitance on the LMK0482x makes external high frequency decoupling capacitors (<1 nF) unnecessary. The internal capacitance is more effective at filtering high frequency noise than off-device bypass capacitance because there is no bond wire inductance between the LMK0482x circuit and the bypass capacitor. For lower-frequency decoupling and voltage stabilization, decoupling capacitors are still beneficial. 11.1.1.1 Clock Output Supplies These supplies include Vcc2_CG1, Vcc3_SYSREF, Vcc4_CG2, Vcc11_CG3, and Vcc12_CG0. If OSCout is used, Vcc7_OSCout can also be considered a clock output supply. Ferrite beads may be used to reduce crosstalk between different clock groups on the same LMK0482x device. Ferrite beads placed between the power supply and a clock group Vcc pin should reduce noise between the Vcc pin and the power supply modestly above 30 MHz. Below 30 MHz, integrated LDOs provide additional noise mitigation. When two clock groups share the same frequency, or if a clock group is not used, a single ferrite bead can be used between the power supply and each same-frequency clock group Vcc pin. When using ferrite beads on clock group Vcc pins, consider the following guidelines to ensure the power supply will source the needed switching current: * In cases with an output frequency > 30 MHz, a ferrite bead may be placed and the internal capacitance is sufficient * If a ferrite bead is used with a low frequency output (< 30 MHz), and the output format is set to a high current switching format such as LVPECL or LCPECL, then: - The ferrite bead can be removed to lower the impedance to the main power supply and bypass capacitors, or - Localized capacitance can be placed between the ferrite bead and Vcc pin to support the switching current. - Note: the decoupling capacitors used between the ferrite bead and a clock group Vcc pin can permit high frequency switching noise to couple through the capacitors into the ground plane and onto other clock VCC pins through their decoupling capacitors. Placing unnecessary decoupling capacitances, or placing ferrite beads with excessive impedance at high frequency (> 200 ) can degrade crosstalk performance. - If the OSCout buffer format is LVCMOS, TI recommends using a complementary output format such as LVCMOS (Norm/Inv) to reduce switching noise and crosstalk. If only a single LVCMOS output is required, the complementary LVCMOS output format can still be used by leaving the unused LVCMOS output floating. * Vcc3_SYSREF powers both the SYSREF divider and the SYNC circuitry. If SYNC is used but the SYSREF divider is not, Vcc3_SYSREF can be connected to any other clock output supply without impacting noise performance. 11.1.1.2 Low-Crosstalk Supplies These supplies include Vcc1_VCO, Vcc5_DIG, and Vcc6_PLL1. Each of these pins has internal bypass capacitance. Ferrite beads should not be needed between these pins and the power supply. A ferrite bead can optionally before the common point connecting these supplies, in which case a large decoupling capacitance (1 F or more) should be used for voltage stability after the ferrite bead. The typical application diagram in Figure 41 shows all these supply pins connected together to the power supply with an optional ferrite bead and decoupling capacitance. 114 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 Pin Connection Recommendations (continued) These supplies are considered low-crosstalk supplies because they do not generate much noise. Vcc1_VCO noise is effectively captured by the on-chip bypass capacitance, since noise from this pin is typically very high frequency. This pin also uses a high-quality integrated LDO to minimize noise below 30 MHz. Vcc5_DIG is only active at startup and during GPIO events, so after startup there is no continuous noise contribution from this pin. Vcc6_PLL1 is usually low-noise as well, due to the low frequency of the PLL1 phase detector. An on-chip LDO regulates this supply and prevents most PLL1 charge pump noise from escaping. If the PLL1 phase detector is set to a high frequency, a ferrite bead may optionally be used on this supply. If a ferrite bead is used with this supply, the DC resistance of this ferrite bead should be minimized to avoid voltage fluctuation at the PLL1 supply/PLL1 charge pump, and a 0.1-F decoupling capacitor should be placed after the ferrite bead close to the supply pin. 11.1.1.3 PLL2 Supplies These supplies include Vcc9_CP2 and Vcc10_PLL2. Each of these pins has an internal bypass capacitor. A ferrite bead should be placed between the power supply and Vcc9. The DC resistance of this ferrite bead should be minimized to avoid voltage fluctuations at the PLL2 charge pump. Typically the frequency of the PLL2 phase detector is >50 MHz and an external decoupling capacitor is not necessary. For lower PLL2 phase detector frequencies, a 0.1-F decoupling capacitor should be placed after the ferrite bead close to the supply pin. Use of a ferrite bead between the power supply and Vcc10_PLL2 is optional. Normally the frequency of the dividers used by PLL2 is high enough that all noise is well-constrained by the on-chip bypass capacitance. If a ferrite bead is used, a 0.1-F decoupling capacitor should be placed after the ferrite bead close to the supply pin. 11.1.1.4 Clock Input Supplies These supplies include Vcc6_PLL1 and Vcc9_OSCin. If CLKin2 is used, Vcc7_OSCout is also included. For Vcc6_PLL1, follow guidance in Low-Crosstalk Supplies. For Vcc9_OSCin, a ferrite bead is recommended for VCXO frequencies above 30 MHz. Typically above 100 MHz no bypass capacitance is necessary on this pin, but if the OSCin frequency is < 100 MHz, a 0.1-F decoupling capacitor should be placed after the ferrite bead close to the supply pin. Vcc7_OSCout should follow similar guidance to Vcc9 for CLKin2 above 30 MHz, and Vcc6_PLL1 for CLKin2 below 30 MHz. When CLKin1 is used as Fin or FBCLKin, TI recommends using CLKin2 as the source to PLL1 whenever possible. CLKin0 and CLKin1 share Vcc6_PLL1 supply, and in cases where Fin or FBCLKin is high frequency, CLKin0 can crosstalk to Fin/FBCLKin through Vcc6_PLL1. CLKin2 is powered from Vcc7_OSCout, and the crosstalk between Fin/FBCLKin and CLKin2 is significantly reduced as a result. 11.1.1.5 Unused Clock Inputs/Outputs Leave unused clock inputs and outputs floating. Set unused clock outputs to powerdown format, and disable unused channel pairs. If the SYSREF is not used in a channel pair, SDCLKoutY_PD can be set. For maximum power savings and noise immunity, set DCLKoutX_PD, SDCLKoutY_PD, and CLKoutX_Y_PD on all unused channel pairs. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 115 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 11.2 Current Consumption / Power Dissipation Calculations From Table 87, the current consumption can be calculated for any configuration. The data below is typical and not assured. The TICS Pro device profiles for LMK0482x family devices also include a current calculator, which performs realtime analysis of the register settings and estimates the current consumption based on which blocks are enabled. TI strongly recommends using TICS Pro to compute the current for any device profile, as it is faster and more flexible than manual computation using the table below. TICS Pro does not require a connection to the LMK0482x to generate a current consumption estimate or a register file. Table 87. Typical Current Consumption for Selected Functional Blocks (TA = 25 C, VCC = 3.3 V) BLOCK TYPICAL ICC (mA) POWER DISSIPATED in DEVICE (mW) PLL1 and PLL2 locked 131.5 433.95 LMK04826/LMK04828 13.5 44.55 22 72.6 CONDITION CORE and FUNCTIONAL BLOCKS Core Dual loop, internal VCO0 VCO (with VCO divider for LMK04821) VCO1 is selected OSCin Doubler Doubler is enabled 3 9.9 CLKin Any one of the CLKinX is enabled 4.9 16.17 Holdover is enabled HOLDOVER_EN = 1 1.3 4.29 Hitless switch is enabled HOLDOVER_HITLESS_SWI TCH = 1 0.9 2.97 Track mode TRACK_EN = 1 Holdover SYNC_EN = 1 SYSREF LMK04821 EN_PLL2_REF_2X = 1 2.5 8.25 Required for SYNC and SYSREF functionality 7.6 25.08 Enabled SYSREF_PD = 0 27.2 89.76 Dynamic digital delay enabled SYSREF_DDLY_PD = 0 5 16.5 Pulser is enabled SYSREF_PLSR_PD = 0 4.1 13.53 SYSREF pulses mode SYSREF_MUX = 2 3 9.9 SYSREF continuous mode SYSREF_MUX = 3 3 9.9 66.33 CLOCK GROUP Enabled Any one of the CLKoutX_Y_PD = 0 20.1 IDL Any one of the CLKoutX_Y_IDL = 1 2.2 7.26 ODL Andy one of the CLKoutX_Y_ODL = 1 3.2 10.56 Divider only DCLKoutX_MUX = 0 13.6 44.88 Divider + DCC + HS DCLKoutX_MUX = 1 17.7 58.41 Analog delay + divider DCLKoutX_MUX = 3 13.6 44.88 Clock Divider CLOCK OUTPUT BUFFERS LVDS 100- differential termination HSDS 6 19.8 HSDS 6 mA, 100- differential termination 8.8 29.04 HSDS 8 mA, 100- differential termination 11.6 38.28 HSDS 10 mA, 100- differential termination 19.4 64.02 100- differential termination 18.5 61.05 OSCout BUFFERS LVDS LVCMOS 116 LVCMOS pair 150 MHz 42.6 140.58 LVCMOS single 150 MHz 27 89.1 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 12 Layout 12.1 Layout Guidelines 12.1.1 Thermal Management Power consumption of the LMK0482x family of devices can be high enough to require attention to thermal management. For reliability and performance reasons, the die temperature should be limited to a maximum of 125C. That is, as an estimate, TA (ambient temperature) plus device power consumption multiplied by RJA should not exceed 125C. The package of the device has an exposed pad that provides the primary heat removal path, as well as excellent electrical grounding to a printed circuit board. To maximize the removal of heat from the package, a thermal land pattern, including multiple vias to a ground plane, must be incorporated on the PCB within the footprint of the package. The exposed pad must be soldered down to ensure adequate heat conduction out of the package. 7.2 mm 0.2 mm 1.46 mm 1.15 mm Figure 42. Recommended Land and Via Pattern Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 117 LMK04821, LMK04826, LMK04828 SNAS605AS - MARCH 2013 - REVISED MAY 2020 www.ti.com 12.2 Layout Example Figure 43. LMK0482x Layout Example 118 Submit Documentation Feedback Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 LMK04821, LMK04826, LMK04828 www.ti.com SNAS605AS - MARCH 2013 - REVISED MAY 2020 13 Device and Documentation Support 13.1 Device Support 13.1.1 Development Support 13.1.1.1 PLLatinum Sim Loop filter design and simulation. For PLLatinum Sim, go to www.ti.com/tool/PLLATINUMSIM-SW. 13.1.1.2 TICS Pro EVM programming software. Can also be used to generate register map for programming for a specific application. For TICS Pro, go to www.ti.com/tool/TICSPRO-SW 13.2 Related Links The table below lists quick access links. Categories include technical documents, support and community resources, tools and software, and quick access to sample or buy. Table 88. Related Links PARTS PRODUCT FOLDER SAMPLE & BUY TECHNICAL DOCUMENTS TOOLS & SOFTWARE SUPPORT & COMMUNITY LMK04821 Click here Click here Click here Click here Click here LMK04826 Click here Click here Click here Click here Click here LMK04828 Click here Click here Click here Click here Click here 13.3 Trademarks PLLatinum is a trademark of Texas Instruments. All other trademarks are the property of their respective owners. 13.4 Electrostatic Discharge Caution These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 13.5 Glossary SLYZ022 -- TI Glossary. This glossary lists and explains terms, acronyms, and definitions. 14 Mechanical, Packaging, and Orderable Information The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation. Copyright (c) 2013-2020, Texas Instruments Incorporated Product Folder Links: LMK04821 LMK04826 LMK04828 Submit Documentation Feedback 119 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (C) Device Marking (3) (4/5) (6) LMK04821NKDR ACTIVE WQFN NKD 64 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04821NKD LMK04821NKDT ACTIVE WQFN NKD 64 250 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04821NKD LMK04826BISQ/NOPB ACTIVE WQFN NKD 64 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04826BISQ LMK04826BISQE/NOPB ACTIVE WQFN NKD 64 250 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04826BISQ LMK04826BISQX/NOPB ACTIVE WQFN NKD 64 2000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04826BISQ LMK04828BISQ/NOPB ACTIVE WQFN NKD 64 1000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04828BISQ LMK04828BISQE/NOPB ACTIVE WQFN NKD 64 250 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04828BISQ LMK04828BISQX/NOPB ACTIVE WQFN NKD 64 2000 RoHS & Green SN Level-3-260C-168 HR -40 to 85 K04828BISQ (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of <=1000ppm threshold. Antimony trioxide based flame retardants must also meet the <=1000ppm threshold requirement. (3) MSL, Peak Temp. - The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) There may be additional marking, which relates to the logo, the lot trace code information, or the environmental category on the device. (5) Multiple Device Markings will be inside parentheses. Only one Device Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a continuation of the previous line and the two combined represent the entire Device Marking for that device. Addendum-Page 1 Samples PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 (6) Lead finish/Ball material - Orderable Devices may have multiple material finish options. Finish options are separated by a vertical ruled line. Lead finish/Ball material values may wrap to two lines if the finish value exceeds the maximum column width. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. OTHER QUALIFIED VERSIONS OF LMK04828 : * Enhanced Product: LMK04828-EP NOTE: Qualified Version Definitions: * Enhanced Product - Supports Defense, Aerospace and Medical Applications Addendum-Page 2 PACKAGE MATERIALS INFORMATION www.ti.com 20-Feb-2020 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing LMK04821NKDR WQFN NKD 64 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 1000 330.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 LMK04821NKDT WQFN NKD 64 250 178.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 LMK04826BISQ/NOPB WQFN NKD 64 1000 330.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 LMK04826BISQE/NOPB WQFN NKD 64 250 178.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 LMK04826BISQX/NOPB WQFN NKD 64 2000 330.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 LMK04828BISQ/NOPB WQFN NKD 64 1000 330.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 LMK04828BISQE/NOPB WQFN NKD 64 250 178.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 LMK04828BISQX/NOPB WQFN NKD 64 2000 330.0 16.4 9.3 9.3 1.3 12.0 16.0 Q1 Pack Materials-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 20-Feb-2020 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LMK04821NKDR WQFN NKD 64 1000 367.0 367.0 38.0 LMK04821NKDT WQFN NKD 64 250 210.0 185.0 35.0 LMK04826BISQ/NOPB WQFN NKD 64 1000 367.0 367.0 38.0 LMK04826BISQE/NOPB WQFN NKD 64 250 210.0 185.0 35.0 LMK04826BISQX/NOPB WQFN NKD 64 2000 367.0 367.0 38.0 LMK04828BISQ/NOPB WQFN NKD 64 1000 367.0 367.0 38.0 LMK04828BISQE/NOPB WQFN NKD 64 250 210.0 185.0 35.0 LMK04828BISQX/NOPB WQFN NKD 64 2000 367.0 367.0 38.0 Pack Materials-Page 2 PACKAGE OUTLINE NKD0064A WQFN - 0.8 mm max height SCALE 1.600 WQFN 9.1 8.9 B A PIN 1 INDEX AREA 0.5 0.3 9.1 8.9 0.3 0.2 DETAIL OPTIONAL TERMINAL TYPICAL 0.8 MAX C SEATING PLANE (0.1) TYP 7.2 0.1 SEE TERMINAL DETAIL 32 17 60X 0.5 33 16 4X 7.5 1 PIN 1 ID (OPTIONAL) 48 64 49 64X 0.5 0.3 64X 0.3 0.2 0.1 0.05 C A C B 4214996/A 08/2013 NOTES: 1. All linear dimensions are in millimeters. Dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. The package thermal pad must be soldered to the printed circuit board for thermal and mechanical performance. www.ti.com EXAMPLE BOARD LAYOUT NKD0064A WQFN - 0.8 mm max height WQFN ( 7.2) SYMM 64X (0.6) 64X (0.25) 64 SEE DETAILS 49 1 48 60X (0.5) SYMM (8.8) (1.36) TYP ( 0.2) VIA TYP 8X (1.31) 16 33 32 17 (1.36) TYP 8X (1.31) (8.8) LAND PATTERN EXAMPLE SCALE:8X 0.07 MIN ALL AROUND 0.07 MAX ALL AROUND METAL SOLDER MASK OPENING SOLDER MASK OPENING NON SOLDER MASK DEFINED (PREFERRED) METAL SOLDER MASK DEFINED SOLDER MASK DETAILS 4214996/A 08/2013 NOTES: (continued) 4. This package is designed to be soldered to a thermal pad on the board. For more information, refer to QFN/SON PCB application note in literature No. SLUA271 (www.ti.com/lit/slua271). www.ti.com EXAMPLE STENCIL DESIGN NKD0064A WQFN - 0.8 mm max height WQFN SYMM 64X (0.6) 64X (0.25) (1.36) TYP 64 49 1 48 (1.36) TYP 60X (0.5) SYMM (8.8) METAL TYP 33 16 32 17 25X (1.16) (8.8) SOLDERPASTE EXAMPLE BASED ON 0.125mm THICK STENCIL EXPOSED PAD 65% PRINTED SOLDER COVERAGE BY AREA SCALE:10X 4214996/A 08/2013 NOTES: (continued) 5. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. 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