GS1679 Cable Driver with HD/SD Capability The GS1679 is a high-speed BiCMOS integrated circuit designed to drive one to four 75 coaxial cables. The GS1679 can drive data rates up to 1.485Gb/s, and provides two selectable slew rates in order to achieve compliance to SMPTE 292M, SMPTE 259M and SMPTE 344M. The GS1679 accepts industry-standard differential input levels, including LVPECL and CML. The DISABLE1 and DISABLE2 pins power-down the first and second output drivers respectively, leaving the serial data output in a high-impedance state. The GS1679 features an adjustable output swing using an external bias resistor. The single-ended output swing is adjustable from 600mVpp to 1200mVpp. The GS1679 can be powered from either a 3.3V or a 2.5V supply. Power consumption is typically 110mW using a 2.5V power supply. The GS1679 is forward footprint-compatible with Gennum s 3G GS2989, allowing for an easier migration of HD designs to 3G. 100mV sensitivity Key Features SMPTE 292M, SMPTE 259M and SMPTE 344M Supports DC-coupling to industry-standard compliant differential logic Supports data rates from 270Mb/s to 1.485Gb/s on-chip 100 differential data input termination Supports DVB-ASI at 270Mb/s Excellent output eye quality Dual differential coaxial-cable-driving outputs Power supply operation at 3.3V or 2.5V selectable slew rates 110mW power consumption (2.5V supply) adjustable output swing from 600mVpp to Operating temperature range: -40C to +85C 1200mVpp Small footprint QFN package (4mm x 4mm) DISABLE control Pb-free and RoHS compliant Wide common-mode range input buffer Forward pin-compatible with Gennum s 3G GS2989 Typical Application Circuit VCC VCC Term 10n 10n GND 10n 75R 5n6* GND 12 4u7 SDO1 75R 4u7 11 75R SDO1 2 DDI VCC Term 5n6* 4u7 75R 3 DDI GS1679 GND 10n VCC 75R 5n6* 5 10 4u7 RSET SDO2 4u7 75R R* 75R 9 SDO2 VCC Term 5n6* 4u7 75R GND 10n *Customer to choose resistor value. GND NOTE: All resistors in Ohms, capacitors in Farads, * Typical value: varies with layout, and represents a trade-off and inductors in Henrys, unless otherwise stated. between good eye shape and output return loss. 5n6 is the optimum value for an 800mV output swing and 3.3V operation. 4n7 is the optimum value for an 800mV output swing and 2.5V operation. 6n8 is the optimum value for an 1200mV output swing. GS1679 Cable Driver with HD/SD Capability 1 of 16 www.gennum.com Data Sheet 54175 - 1 March 2011 1 VCC 4 8 VEE VCC 13 VEE 15 14 SD/HD NC 6 16 DISABLE1 NC 7 DISABLE2Contents Key Features........................................................................................................................................................1 Typical Application Circuit.............................................................................................................................1 1. Pin Out...............................................................................................................................................................3 1.1 Pin Assignment ..................................................................................................................................3 1.2 Pin Descriptions ................................................................................................................................3 2. Electrical Characteristics ............................................................................................................................4 2.1 Absolute Maximum Ratings ..........................................................................................................4 2.2 DC Electrical Characteristics ........................................................................................................5 2.3 AC Electrical Characteristics ........................................................................................................6 3. Detailed Description.....................................................................................................................................7 3.1 Serial Data Input ...............................................................................................................................7 3.2 Serial Digital Output ........................................................................................................................7 3.2.1 Slew Rate Selection (Rise/Fall Time Requirement)....................................................7 3.3 Output Disable ...................................................................................................................................8 3.4 Output Amplitude (RSET) ..............................................................................................................8 4. Application Information .......................................................................................................................... 10 4.1 PCB Layout ....................................................................................................................................... 10 4.2 Typical Application Circuit ........................................................................................................ 10 5. Input/Output Circuits ............................................................................................................................... 11 6. Package & Ordering Information .......................................................................................................... 12 6.1 Package Dimensions ..................................................................................................................... 12 6.2 Recommended PCB Footprint ................................................................................................... 13 6.3 Packaging Data ............................................................................................................................... 13 6.4 Solder Reflow Profiles .................................................................................................................. 14 6.5 Marking Diagram ........................................................................................................................... 14 6.6 Ordering Information ................................................................................................................... 15 Revision History .............................................................................................................................................. 16 GS1679 Cable Driver with HD/SD Capability 2 of 16 Data Sheet 54175 - 1 March 2011