GS1674-INE3 Semtech

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. Programmable carrier detect with squelch threshold Key Features adjustment Replaces the LMH0044 Standard EIA/JEDEC logic control and status signal SMPTE 292M, SMPTE 344M and SMPTE 259M levels compliant Single 3.3V power supply operation Automatic cable equalization 195mW power consumption (typical) Performance optimized for 270Mb/s and 1.485Gb/s. Typical equalized length of Belden 1694A cable: 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. Supports DVB-ASI at 270Mb/s Pb-free and RoHS compliant Manual bypass (useful for low data rates with slow rise/fall times) Typical Application Circuit CD MUTE VCC VCC 16 15 14 13 10nF 10nF 6.8nH* 1 12 VEE D 4.7F SDI VEE A + SDO 1F 2 11 SDI SDO 75 GS1674 3 1F 10 SDI SDO + SDO 4 9 75 37.4 4.7F VEE A VEE D 56 7 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 1 of 16 www.semtech.com Data Sheet 54168 - 2 September 2012 VCC A AGC AGC CD BYPASS MUTE SQ ADJ VCC DContents 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 2 of 16 Data Sheet 54168 - 2 September 2012