DS1181L 20MHz to 134MHz Spread-Spectrum Clock Modulator for LCD Panels General Description Features The DS1181L is a spread-spectrum clock modulator IC that reduces EMI in high clock-frequency-based, digital electronic equipment. Using an integrated phase-locked loop (PLL), the DS1181L accepts an input clock signal in the range of 20MHz to 134MHz and delivers a spread-spectrum modulated output clock signal. The PLL modulates, or dithers, the output clock about the center input frequency at a pin-selectable magnitude, allowing direct EMI control and optimization. In addition, through an enable pin the dithering can be enabled or disabled for easy comparison of system performance during EMI testing. This same input pin also allows the DS1181L output to be three-stated. By dithering the system clock, all the address, data, and timing signals generated from this signal are also dithered so that the measured EMI at the fundamental and harmonic frequencies is greatly reduced. This is accomplished without changing clock rise/fall times or adding the space, weight, design time, and cost associated with mechanical shielding. The DS1181L is provided in an 8-pin TSSOP package and operates over a full automotive temperature range of -40C to +125C. Applications LCD Panels for TVs, Desktop Monitors, and Notebook and Tablet PCs Printers Modulates a 20MHz to 134MHz Clock with Center Spread-Spectrum Dithering Selectable Spread-Spectrum Modulation Magnitudes of: 0.5% 1.0% 1.5% 2.0% Low 75ps Cycle-to-Cycle Jitter Spread-Spectrum Disable Mode Pin Compatible with Alliance/PulseCore Semiconductor P2040 Series Devices Clock Output Disable Low Cost Low Power Consumption 3.3V Single Voltage Supply -40C to +125C Temperature Range Small 8-Pin TSSOP Package Ordering Information TEMP RANGE PIN-PACKAGE DS1181LE+ PART -40C to +125C 8 TSSOP DS1181LE+T -40C to +125C 8 TSSOP +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. Typical Operating Circuit appears at end of data sheet. Block Diagram Pin Configuration VCC DS1181L CLKIN fIN = 20MHz TO 134MHz VCC PLL WITH CENTERDITHERED SPREADSPECTRUM SSO fSSO = 20MHz to 134MHz (DITHERED) ENABLE LOGIC CRSEL SMSEL1 SMSEL2 19-7502; Rev 2; 2/15 SSEN TOP VIEW CLKIN 1 SMSEL1 2 SMSEL2 3 + 8 VCC DS1181L GND 4 CONFIGURATION DECODE AND CONTROL GND TSSOP 7 CRSEL 6 SSO 5 SSEN DS1181L 20MHz to 134MHz Spread-Spectrum Clock Modulator for LCD Panels Absolute Maximum Ratings Voltage Range on VCC Relative to GND..............-0.5V to +4.3V Voltage Range on Any Lead Relative to GND.................-0.5V to (VCC + 0.5V), not to exceed +4.3V Operating Temperature Range.......................... -40C to +125C Storage Temperature Range............................. -55C to +125C Soldering Temperature...................See J-STD-020 Specification Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Recommended Operating Conditions (TA = -40C to +125C, unless otherwise noted.) PARAMETER SYMBOL Supply Voltage VCC Input Logic 1 VIH Input Logic 0 VIL Input Logic Float (SSEN, CRSEL) SSO Load CLKIN Duty Cycle (Note 1) MIN TYP MAX UNITS 3.0 0.8 x 3.6 VCC + V VCC 0.3 0.2 x -0.3 IFLOAT CL CLKIN Frequency CONDITIONS VCC 1 0V < VIN < VCC SSO < 80MHz 15 80MHz SSO < 134MHz 7 fIN fINDC V V A pF 20 134 MHz 40 60 % MAX UNITS 18 mA DC Electrical Characteristics (VCC = +3.0V to +3.6V, TA = -40C to +125C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS Supply Current ICC CL = 7pF, fIN = 134MHz SMSEL1/SMSEL2/CLKIN Input Leakage IIL:1 0V < VIN < VCC IOZ SSEN = float CRSEL/SSEN Input Leakage IIL:2 Output Leakage (SSO) Low-Level Output Voltage (SSO) VOL High-Level Output Voltage (SSO) VOH 0V < VIN < VCC IOL = 4mA IOH = -4mA MIN TYP -1 +1 A -100 +100 A -1 +1 A 0.4 V 2.4 V AC Electrical Characteristics (VCC = +3.0V to +3.6V, TA = -40C to +125C, unless otherwise noted.) PARAMETER SSO Duty Cycle SSO Rise Time SSO Fall Time Peak Cycle-to-Cycle Jitter Power-Up Time SYMBOL fSSODC tR tF tJ tPOR CONDITIONS Measured at VCC/2 MIN TYP 40 MAX 60 UNITS % CL = 7pF 1 ns 1 ns TA = -40C to +85C, 10,000 cycles 75 ps CL = 7pF (Note 2) 50 ms Note 1: All voltages referenced to ground. Currents into the IC are positive and out of the IC are negative. Note 2: Time between power applied to device and stable output. www.maximintegrated.com Maxim Integrated 2 DS1181L 20MHz to 134MHz Spread-Spectrum Clock Modulator for LCD Panels Typical Operating Characteristics (TA = +25C, unless otherwise noted.) fCLKIN = 20MHz 4 3.2 3.3 3.4 3.5 10 60 110 DS1181L toc03 CL = 7pF 20 40 60 80 100 120 DUTY CYCLE vs. SUPPLY VOLTAGE DUTY CYCLE vs. TEMPERATURE SPECTRUM ATTENUATION vs. FREQUENCY AT DIFFERENT DITHER AMPLITUDES 60 58 56 50 48 46 54 52 50 48 46 44 44 42 42 3.1 3.2 3.3 VCC (V) www.maximintegrated.com 3.4 3.5 3.6 40 fOUT = 72MHz 0.5% 1% 10dB 13dB 1.5% 15dB 17dB 2% ATTENUATION (dB) DUTY CYCLE (%) 52 fCLKIN = 72MHz DS1181L toc06 FREQUENCY (MHz) fCLKIN = 72MHz 3.0 -40 0 TEMPERATURE (C) 54 40 6 VCC (V) 56 DUTY CYCLE (%) 3.6 CL = 7pF DS1181L toc05 58 3.1 DS1181L toc04 60 3.0 VCC = 3.0V 2 2 CL = 7pF 0 VCC = 3.6V 4 4 2 0 10 8 fCLKIN = 20MHz 6 SUPPLY CURRENT vs. FREQUENCY 12 fCLKIN = 66MHz 8 ICC (mA) ICC (mA) 6 fCLKIN = 134MHz 10 fCLKIN = 66MHz 8 SUPPLY CURRENT vs. TEMPERATURE ICC (mA) fCLKIN = 134MHz 10 12 DS1181L toc02 SUPPLY CURRENT vs. SUPPLY VOLTAGE DS1181L toc01 12 fRBW = 120KHz CENTER DITHER -40 10 60 TEMPERATURE (C) 110 FREQUENCY (MHz) Maxim Integrated 3 DS1181L 20MHz to 134MHz Spread-Spectrum Clock Modulator for LCD Panels Pin Description PIN NAME 1 CLKIN 2 SMSEL1 3 FUNCTION Clock Input. 20MHz to 134MHz clock input (fIN). Spread-Spectrum Magnitude Select Inputs. These digital inputs select the desired spread-spectrum magnitude as shown in the table below. SMSEL2 SMSEL1 MAGNITUDE SELECTED (%) 0 0 2.0 0 1 1.5 1 0 1.0 1 1 0.5 SMSEL2 4 GND Ground Spread-Spectrum Enable. Three-level input to enable/disable spread-spectrum and to three-state the output. 5 SSEN 0 = Power-up/spread-spectrum enabled Float = SSO three-stated 1 = Power-up/spread-spectrum disabled (not a bypass mode). 6 SSO Spread-Spectrum Clock Output. Outputs a center-dithered spread-spectrum version of the clock input at CLKIN. Clock Range and Dither Rate Select. Three-level input that determines the dither rate. See the Detailed Description section for details. 7 CRSEL 8 VCC CRSEL CLKIN RANGE (MHz) 0 66 to 134 Float 33 to 80 1 20 to 38 DITHER RATE fIN/832 Supply Voltage Detailed Description Spread-Spectrum Dither Rate The DS1181L modulates an input clock to generate a center-dithered spread-spectrum output. A 20MHz to 134MHz clock is applied to the CLKIN pin. An internal PLL dithers the output clock about its center frequency at a user-selectable magnitude. Spread-Spectrum Dither Magnitude The DS1181L can generate dither magnitudes up to 2%. The desired magnitude is selected using input pins SMSEL1 and SMSEL2 as shown in Table 1. The output spread-spectrum dither rate is fixed at fIN/832. Table 2. Dither Rate CRSEL CLKIN RANGE (MHz) 0 66 to 134 Float 33 to 80 1 20 to 38 DITHER RATE fIN/832 Table 1. Dither Magnitude SMSEL2 SMSEL1 MAGNITUDE SELECTED (%) 0 0 2.0 0 1 1.5 1 0 1.0 1 1 0.5 www.maximintegrated.com Maxim Integrated 4 DS1181L 20MHz to 134MHz Spread-Spectrum Clock Modulator for LCD Panels Applications Information Spread-Spectrum Enable On power-up, the output clock (SSO) remains three-stated until the internal PLL reaches a stable frequency. The SSEN input can be used to disable the spread-spectrum modulation and to three-state the SSO output. If the SSEN pin is pulled high, the spread-spectrum modulation is turned off, but the device still uses the internal PLL to generate the clock signal at SSO. If the SSEN pin is floated, the output is three-stated. Power-Supply Decoupling To achieve best results, it is highly recommended that a decoupling capacitor is used on the IC power-supply pins. Typical values of decoupling capacitors are 0.01F and 0.1F. Use a high-quality, ceramic, surface-mount capacitor, and mount it as close as possible to the VCC and GND pins of the IC to minimize lead inductance. IF SSEN = 1 fIN + (0.5%, 1.0%, 1.5%, OR 2.0% OF fIN) DITHER AMOUNT (0.5%, 1.0%, 1.5%, OR 2.0%) fIN fIN - (0.5%, 1.0%, 1.5%, OR 2.0% OF fIN) 1 fSSO CLKIN RANGE (MHz) 20 TO 134 DITHER CYCLE RATE DITHER RATE fIN/832 TIME Figure 1. DS1181L Spread-Spectrum Frequency Modulation Typical Operating Circuit VCC fIN = 20MHz TO 134MHz VCC CLKIN DECOUPLING CAPACITOR CRSEL SMSEL1 SMSEL2 GND DS1181L SSO SSEN fSSO DITHERED NOTE: IN THE ABOVE CONFIGURATION WITH SMSEL1, SMSEL2, AND SSEN CONNECTED TO GND AS WELL AS CRSEL CONNECTED TO VCC, THE DEVICE IS CONFIGURED WITH A SPREAD-SPECTRUM MAGNITUDE OF 2.0%, AND ALLOWS A CLKIN BETWEEN 20MHz and 38MHz. Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. PACKAGE TYPE PACKAGE CODE DOCUMENT NO. LAND PATTERN NO. 8 TSSOP H8+3 21-0175 90-0248 www.maximintegrated.com Maxim Integrated 5 DS1181L 20MHz to 134MHz Spread-Spectrum Clock Modulator for LCD Panels Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 11/07 Initial release. -- 1 8/08 Increased the absolute maximum ratings range from +3.63V to +4.3V. 2 2 2/15 Removed automotive reference from data sheet 1 DESCRIPTION For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2015 Maxim Integrated Products, Inc. 6 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: DS1181LE+ DS1181LE+T