GS1674 GS1674 Adaptive Cable Equalizer The GS1674 is a high-speed BiCMOS integrated circuit designed to equalize and restore signals received over 75 coaxial cable. The device is optimized for performance at 270Mb/s and 1.485Gb/s, and features DC restoration to compensate for the DC content of SMPTE pathological test patterns. The Carrier Detect output pin (CD) indicates whether a valid input signal has been detected. It can be connected directly to the MUTE pin to mute the output on loss of carrier. The sensitivity of the carrier detect can be easily programmed to allow the GS1674 to distinguish between low-amplitude SDI signals and noise at the input of the device. The equalizing and DC restore stages are disengaged when the BYPASS pin is HIGH. No equalization occurs in Bypass mode. The GS1674 is footprint and drop-in compatible with existing GS1574A and LMH0044 designs, with no additional application changes required. Key Features * Programmable carrier detect with squelch threshold adjustment * Replaces the LMH0044 * SMPTE 292M, SMPTE 344M and SMPTE 259M compliant * Standard EIA/JEDEC logic control and status signal levels * Automatic cable equalization * Single 3.3V power supply operation * Performance optimized for 270Mb/s and 1.485Gb/s. Typical equalized length of Belden 1694A cable: * 195mW power consumption (typical) * Wide temperature range of -40C to +85C 220m at 1.485Gb/s * Small footprint QFN package (4mm x 4mm) 400m at 270Mb/s * Drop-in compatible with the GS1574A. Forward compatible with Gennum's 3G EQ products. * Pb-free and RoHS compliant * Supports DVB-ASI at 270Mb/s * Manual bypass (useful for low data rates with slow rise/fall times) Typical Application Circuit CD MUTE VCC VCC 1F 2 14 13 VCC_D 1 CD VCC_A 6.8nH* SDI 15 MUTE 16 10nF 10nF VEE_D VEE_A SDI SDO 75 12 4.7F + 11 SDO GS1674 SDI VEE_A 5 6 7 SQ_ADJ SDO AGC 37.4 4 BYPASS 75 3 AGC 1F VEE_D 10 + 9 SDO 4.7F 8 SQ_ADJ 1F BYPASS NOTE: All resistors in Ohms, capacitors in Farads, and inductors in Henrys, unless otherwise noted. * Value dependent on layout GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 www.semtech.com 1 of 16 Contents Key Features ........................................................................................................................................................1 Typical Application Circuit.............................................................................................................................1 1. Pin Out...............................................................................................................................................................3 1.1 GS1674 Pin Assignment .................................................................................................................3 1.2 GS1674 Pin Descriptions ................................................................................................................3 2. Electrical Characteristics ............................................................................................................................5 2.1 Absolute Maximum Ratings ..........................................................................................................5 2.2 DC Electrical Characteristics ........................................................................................................5 2.3 AC Electrical Characteristics ........................................................................................................6 2.4 Typical Performance Curves ........................................................................................................7 3. Detailed Description.....................................................................................................................................8 3.1 Serial Data Inputs .............................................................................................................................8 3.2 Cable Equalization ...........................................................................................................................8 3.3 Programmable Squelch Adjust (SQ_ADJ) .................................................................................9 3.4 Mute and Carrier Detect .................................................................................................................9 3.5 Output Rise/Fall Times ................................................................................................................ 10 4. Application Information .......................................................................................................................... 11 4.1 High-Gain Adaptive Cable Equalizers .................................................................................... 11 4.2 PCB Layout ....................................................................................................................................... 11 4.3 Typical Application Circuit ........................................................................................................ 11 5. Input/Output Circuits ............................................................................................................................... 12 6. Package & Ordering Information .......................................................................................................... 13 6.1 Package Dimensions ..................................................................................................................... 13 6.2 Packaging Data ............................................................................................................................... 13 6.3 Recommended PCB Footprint ................................................................................................... 14 6.4 Marking Diagram ........................................................................................................................... 14 6.5 Solder Reflow Profiles .................................................................................................................. 15 6.6 Ordering Information ................................................................................................................... 15 Revision History .............................................................................................................................................. 16 GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 2 of 16 1. Pin Out 2 SDI 3 VEE_A 4 MUTE VCC_D CD 14 13 GS1674 16-pin QFN (top view) 12 VEE_D 11 SDO 10 SDO 9 5 AGC Ground Pad (bottom of package) 6 7 VEE_D 8 SQ_ADJ SDI 15 BYPASS 1 16 AGC VEE_A VCC_A 1.1 GS1674 Pin Assignment Figure 1-1: GS1674 Pin Out 1.2 GS1674 Pin Descriptions Table 1-1: GS1674 Pin Descriptions Pin Number Name Timing Type Description 1, 4 VEE_A Analog Power Most negative power supply for analog circuitry. Connect to GND. 2, 3 SDI, SDI Analog Input 5, 6 AGC, AGC Analog - Serial digital differential input. External AGC capacitor. Connect pin 5 and pin 6 together as shown in the GS1674 Typical Application Circuit on page 11. 7 BYPASS Not Synchronous Input Forces the Equalizing and DC RESTORE stages into bypass mode when HIGH. No equalization occurs in this mode. (Internal pull-down). 8 SQ_ADJ Analog Input Squelch Adjust. Adjusts the approximate amount of cable equalized before CD goes low. See Section 3.3 and Section 3.4. (Internal pull-down). 9, 12 VEE_D Analog Power Most negative power supply for the digital circuitry and output buffer. Connect to GND. 10, 11 SDO, SDO GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 Analog Output Equalized serial digital differential output. 3 of 16 Table 1-1: GS1674 Pin Descriptions (Continued) Pin Number Name Timing Type 13 VCC_D Analog Power Description Most positive power supply for the digital I/O pins of the device. Connect to +3.3V DC. 14 MUTE Not Synchronous Input CONTROL SIGNAL INPUT levels are LVCMOS/LVTTL compatible. (3.3V Tolerant) Controls output behaviour on SDO and SDO. (Internal pull-down). See Section 3.4. 15 CD Not Synchronous Output STATUS SIGNAL OUTPUT Signal levels are LVCMOS/LVTTL compatible. Indicates the presence of an input signal. See Section 3.4. 16 VCC_A Analog Power Most positive power supply for the analog circuitry of the device. Connect to +3.3V DC. - Center Pad - Power Internally bonded to VEE_A. NOTE: For 3G migration, pins 4 and 9 are input select pins. GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 4 of 16 2. Electrical Characteristics 2.1 Absolute Maximum Ratings Parameter Value Supply Voltage -0.5V to +3.6V DC Input ESD Voltage (HBM) 5kV Storage Temperature Range -50C < Ts < 125C Input Voltage Range (any input) -0.3 to (VCC +0.3)V Operating Temperature Range -20C to +85C Functional Temperature Range -40C to +85C Solder Reflow Temperature 260C 2.2 DC Electrical Characteristics Table 2-1: DC Electrical Characteristics VCC = 3.3V 5%, TA = -20C to +85C, unless otherwise shown Parameter Symbol Conditions Min Typ Max Units Notes 3.135 3.3 3.465 V - Supply Voltage VCC - Power Consumption PD TA = 25C - 195 250 mW - Supply Current Is TA = 25C - 59 - mA - VCMOUT TA = 25C - VCC - (VSDO)/2 - V - Input Common Mode Voltage VCMIN TA = 25C - 1.8 - V - SQ_ADJ DC Voltage (to mute signal) - 0m, TA = 25C - 3.2 - V - SQ_ADJ Range - TA = 25C - 0.9 - V - 2.4 - - V - - - 0.4 V - 2.0 - - V - - - 0.8 V - Output Common Mode Voltage CD Output Voltage VCD(OH) Carrier not present VCD(OL) Carrier present Mute Input Voltage Required to Force Outputs to Mute VMute Min to Mute Mute Input Voltage Required to Force Outputs Active VMute Max to Activate GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 5 of 16 2.3 AC Electrical Characteristics Table 2-2: AC Electrical Characteristics VCC = 3.3V 5%, TA = -20C to +85C, unless otherwise shown Parameter Symbol Conditions Min Typ Max Units Notes Serial input data rate DRSDO - 143 - 1485 Mb/s - Input Voltage Swing VSDI TA =25C, differential, 270Mb/s and 1.485Gb/s 720 800 950 mVp-p 1 Output Voltage Swing VSDO 100 load, TA =25C, differential 680 800 900 mVp-p - - 1.485Gb/s Belden 1694A: 0-220m - 0.25 - UI - - 270Mb/s Belden 1694A: 0-400m - - 0.2 UI 2, - 1.485Gb/s 20% - 80% 35 65 90 ps - - 270Mb/s (see Section 3.5) Mismatch in rise/fall time - - - - 30 ps - Duty cycle distortion - - - - 30 ps - Overshoot - - - - 10 % - Input Return Loss - - 15 21 - dB - Input Resistance - Single-ended - 1.9 - k - Input Capacitance - Single-ended - 1.3 - pF - Output Resistance - Single-ended - 50 - - Output Jitter of Various Cable Lengths and Data Rates Output Rise/Fall time NOTES: 1. 0m cable length. 2. All parts are production tested. In order to guarantee jitter over the full range of specification (VCC = 3.3V 5%, TA = -20C to +85C, and 720-880mV launch swing from the SDI cable driver) the recommended applications circuit must be used. GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 6 of 16 2.4 Typical Performance Curves VCC=3.3V, room temperature, 800mV launch swing 600 Jitter (ps) 400 200 0 0 100 200 300 400 Cable Length (m) Figure 2-1: Jitter vs. Cable Length (270 Mb/s) 100 Jitter (ps) 80 60 40 20 0 50 100 150 Cable Length (m) Figure 2-2: Jitter vs. Cable Length (1485 Mb/s) GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 7 of 16 3. Detailed Description SQ_ADJ BYPASS MUTE CD Squelch Adjust Carrier Detect Mute SDI SDI Equalizer DC Restore Output SDO SDO AGC AGC AGC Figure 3-1: GS1674 Functional Block Diagram The GS1674 is a high-speed BiCMOS IC designed to equalize serial digital signals. The GS1674 can equalize HD and SD serial digital signals, and will typically equalize 200m at 1.485Gb/s and 400m at 270Mb/s. The GS1674 is powered from a single +3.3V power supply, and consumes approximately 195mW of power. 3.1 Serial Data Inputs The Serial Data Input signals can be connected to the input pins (SDI/SDI) in either a differential or single-ended configuration. AC-coupling of the inputs is recommended, as the SDI and SDI inputs are internally biased at approximately 1.8V. 3.2 Cable Equalization The input signal passes through a variable gain equalizing stage, whose frequency response closely matches the inverse of the cable loss characteristic. In addition, the variation of the frequency response with control voltage imitates the variation of the inverse cable loss characteristic with cable length. The edge energy of the equalized signal is monitored by a detector circuit which produces an error signal corresponding to the difference between the desired edge energy and the actual edge energy. This error signal is integrated by both an internal and an external AGC filter capacitor providing a steady control voltage for the gain stage. As the frequency response of the gain stage is automatically varied by the application of negative feedback, the edge energy of the equalized signal is kept at a constant level which is representative of the original edge energy at the transmitter. The equalized signal is also DC-restored, effectively restoring the logic threshold of the equalized signal to its correct level independent of shifts due to AC-coupling. GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 8 of 16 3.3 Programmable Squelch Adjust (SQ_ADJ) The GS1674 incorporates a programmable Squelch Adjust (SQ_ADJ) threshold. This feature can be useful in applications where there are multiple input channels using the GS1674 and the maximum gain can be limited to avoid crosstalk. The SQ_ADJ pin acts to change the threshold of the Carrier Detect (CD) pin, through voltage level variances. When the input signal drops below a certain threshold, the CD pin will be driven high, indicating that there is not a valid input signal. In order to enable automatic muting of the output of the GS1674, the CD pin should be connected directly to the MUTE pin. In applications where programmable squelch adjust is not required, the SQ_ADJ pin may be left unconnected. Figure 3-2 shows the relationship between the SQ_ADJ voltage and cable length at which CD will assert or deassert. This feature has been designed for use in applications such as routers, where signal crosstalk and circuit noise cause the Equalizer to output erroneous data when no input signal is present. The use of a Carrier Detect function with a fixed internal reference does not solve this problem, since the signal to noise ratio on the circuit board could be significantly less than the default signal detection level set by the on chip reference. 3.2 SQ_ADJ (V) 3.0 2.8 2.6 2.4 2.2 2.0 0 50 100 150 200 250 300 350 400 450 Cable Length (m) Figure 3-2: SQ_ADJ vs. Cable Length (VCC=3.3V, room temperature, 800mV launch swing) 3.4 Mute and Carrier Detect The GS1674 includes a MUTE input pin that allows the application interface to mute the Serial Digital Output at any time. Set the MUTE pin HIGH to mute SDO and SDO. In this case, the outputs will mute regardless of the setting of the BYPASS pin. A Carrier Detect output pin (CD) indicates the presence of a valid signal at the input of the GS1674. When CD is LOW, the device has detected a valid input on SDI and SDI. When CD is HIGH, the device has not detected a valid input. The CD output pin may be connected directly to the MUTE input pin to enable automatic muting of the GS1674 when no valid input signal has been detected. NOTE 1: CD will only detect loss of carrier for data rates greater than 19Mb/s. NOTE 2: If the maximum cable length is exceeded (set by the SQ_ADJ pin) and the device is not in Bypass mode, the CD pin will not be driven low, even if a carrier is present. GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 9 of 16 \ Table 3-1: Mute Input Table Mute Function 0 SDO and SDO operate normally 1 SDO and SDO are forced to a steady state (either HIGH or LOW) Table 3-2: CD Output Table CD Input Status 0 Valid Input on SDI, SDI pins 1 Input is not valid 3.5 Output Rise/Fall Times Rise/Fall Time (ps) 200 0 0 100 200 Cable Length (m) 300 400 Figure 3-3: Typical Rise/Fall Time for 270Mb/s Data Rate (VCC=3.3V, room temperature, 800mV launch swing) The GS1674 was designed to limit bandwidth as cable length is increased. During normal HD (1.485Gb/s), and SD (270Mb/s) operation, the impact of this is minimal on rise and fall time over the operating range from 0-200m. Above 200m, this bandwidth limitation becomes more significant, and reduction in rise and fall time is observed. This means that for SD (270Mb/s) operation at cable lengths greater than 200m, rise and fall times are slow as shown in Figure 3-3 above. This is beneficial because at 270Mb/s, one unit interval is equal to 3.7ns, so rise and fall times less than 100ps are not required, and slower rise and fall times actually help to reduce EMI. GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 10 of 16 4. Application Information 4.1 High-Gain Adaptive Cable Equalizers The GS1674 is Gennum's latest HD-optimized adaptive cable equalizer. In order to continue to extend the cable length that an equalizer will remain operational over, it is necessary to have high-gain in the equalizer. A video cable equalizer must provide wide band gain over a range of frequencies in order to accommodate the range of data rates and signal patterns that are present in a SMPTE compliant serial video stream. The GS1674 has an increase in gain over the GS1574A at critical HD frequencies, and because of this, the GS1674 may be sensitive to signals at the input that the GS1574A will not be sensitive to. Small levels of signal or noise present at the input pins of the Equalizer may cause chatter at the output. In order to prevent this from happening, particular attention must be paid to board layout. 4.2 PCB Layout Special attention must be paid to component layout when designing Serial Digital Interfaces for HDTV. An FR-4 dielectric can be used, however, controlled impedance transmission lines are required for PCB traces longer than approximately 1cm. Note the following PCB artwork features used to optimize performance: * The PCB ground plane is removed under the GS1674 input components to minimize parasitic capacitance * The PCB ground plane is removed under the GS1674 output components to minimize parasitic capacitance * High-speed traces are curved to minimize impedance changes 4.3 Typical Application Circuit CD MUTE VCC VCC 1F 2 14 13 VCC_D 1 CD VCC_A 6.8nH* SDI 15 MUTE 16 10nF 10nF VEE_D VEE_A SDI SDO 75 12 4.7F + 11 SDO GS1674 VEE_A 5 6 7 SQ_ADJ 4 SDO AGC 37.4 SDI BYPASS 75 3 AGC 1F VEE_D 10 + 9 SDO 4.7F 8 SQ_ADJ 1F BYPASS NOTE: All resistors in Ohms, capacitors in Farads, and inductors in Henrys, unless otherwise noted. * Value dependent on layout Figure 4-1: GS1674 Typical Application Circuit GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 11 of 16 5. Input/Output Circuits 4k 4k + SQ_ADJ - SDI SDI RC 5.25k 5.25k Figure 5-1: Input Equivalent Circuit 50 82.4k Figure 5-2: SQ_ADJ Equivalent Circuit 50 SDO SDO Figure 5-3: Output Circuit MUTE, BYPASS Figure 5-4: MUTE and BYPASS Circuits GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 CD Figure 5-5: CD Circuit 12 of 16 6. Package & Ordering Information 6.1 Package Dimensions 2.76+/-0.10 PIN #1 IDENTIFICATION 0.4500 DATUM A PIN 1 AREA 2X 0.40+/-0.05 4.00+/-0.05 B CENTER TAB 2.76+/-0.10 A 4.00+/-0.05 DETAIL B 0.15 C DATUM B 0.15 C 2X 0.35+/-0.05 0.65 0.20 REF 16X 0.10 C C 0.10 CAB 0.05 C DATUM A OR B 16X 0.08 C SEATING PLANE 0.65/2 0.00-0.05 0.85+/-0.05 TERMINAL TIP 0.65 DETAIL B SCALE:NTS 6.2 Packaging Data Parameter Value Package Type 4mm x 4mm 16-pin QFN Package Drawing Reference JEDEC M0220 Moisture Sensitivity Level 3 Junction to Case Thermal Resistance, j-c 31.0C/W Junction to Air Thermal Resistance, j-a (at zero airflow) 43.8C/W Psi, 11.0C/W Pb-free and RoHS compliant Yes GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 13 of 16 6.3 Recommended PCB Footprint 0.35 0.65 0.55 3.70 2.76 Center Pad NOTE: All dimensions are in millimeters. 2.76 3.70 The center pad should be connected to the most negative power supply plane for analog circuitry in the device (VEE_A) by a minimum of 5 vias. NOTE: Suggested dimensions only. Final dimensions should conform to customer design rules and process optimizations. 6.4 Marking Diagram Pin 1 Indicator HD-SDI GS1674 XXXXE3 YYWW GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 GS1674 - Package Mark XXXX - Last 4 digits (excluding decimal) of SAP Batch Assembly (FIN) as listed on Packing Slip E3 - Pb-free & Green Indicator YYWW - Date Code 14 of 16 6.5 Solder Reflow Profiles The GS1674 is available in a Pb-free package. It is recommended that the Pb-free package be soldered with Pb-free paste using the reflow profile shown in Figure 6-1. Temperature 60-150 sec. 20-40 sec. 260C 250C 3C/sec max 217C 6C/sec max 200C 150C 25C Time 60-180 sec. max 8 min. max Figure 6-1: Maximum Pb-free Solder Reflow Profile 6.6 Ordering Information Part Number Package Temperature Range GS1674 GS1674-INE3 16-pin QFN -40C to 85C GS1674 GS1674-INTE3 16-pin QFN Tape & Reel (250pcs) -40C to 85C Revision History Version ECR 2 158586 54547 September 2012 Change in Input ESD Voltage (HBM) parameter in 2.1 Absolute Maximum Ratings 1 154866 - September 2010 Increased cable length to 220m at 1.485Gb/s. 0 154128 - May 2010 Converted to Data Sheet. Changed pin 4 and pin 9 names in Pin Out and Application Information. A 153462 - March 2010 GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 PCN Date Changes and/or Modifications New document. 15 of 16 DOCUMENT IDENTIFICATION CAUTION DATA SHEET ELECTROSTATIC SENSITIVE DEVICES Information relating to this product and the application or design described herein is believed to be reliable, however such information is provided as a guide only and Semtech assumes no liability for any errors in this document, or for the application or design described herein. Semtech reserves the right to make changes to the product or this document at any time without notice. DO NOT OPEN PACKAGES OR HANDLE EXCEPT AT A STATIC-FREE WORKSTATION (c) Semtech 2012 All rights reserved. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. No liability will be accepted by the publisher for any consequence of its use. Publication thereof does not convey nor imply any license under patent or other industrial or intellectual property rights. Semtech assumes no responsibility or liability whatsoever for any failure or unexpected operation resulting from misuse, neglect improper installation, repair or improper handling or unusual physical or electrical stress including, but not limited to, exposure to parameters beyond the specified maximum ratings or operation outside the specified range. SEMTECH PRODUCTS ARE NOT DESIGNED, INTENDED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN LIFE-SUPPORT APPLICATIONS, DEVICES OR SYSTEMS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF SEMTECH PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE UNDERTAKEN SOLELY AT THE CUSTOMER'S OWN RISK. Should a customer purchase or use Semtech products for any such unauthorized application, the customer shall indemnify and hold Semtech and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs damages and attorney fees which could arise. Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. Contact Information Semtech Corporation Gennum Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111, Fax: (805) 498-3804 www.semtech.com GS1674 Adaptive Cable Equalizer Data Sheet 54168 - 2 September 2012 16 of 16 16