General Description
The VSC7962 is a single 3.3V supply combination limiting amplifier and laser diode driver for SONET/SDH applications up to 3.125Gb/s. The limiting amplifier features Loss of Signal (LOS) detect, output offset correction, and optional output squelch. Laser driver data inputs accept differential PECL signals and the output modulation and bias currents are easily controlled via external components. The laser diode driver Automatic Power Control (APC) loop maintains a constant average optical power over temperature and lifetime. The dominant pole of the APC loop can be controlled with an external capacitor. Other features include enable control, short-circuit protection for the modulation and bias inputs, short rise and fall times, and failure-monitor output to indicate when the APC loop is unable to maintain the average optical power. The VSC7962 is available in die form or in a 48-pin TQFP package. The VSC7960 provides similar features to the VSC7962 but the limiting amplifier has CML outputs.

FEATUREs
• 3.3V Power Supply
• Laser Driver AC-Coupled to Laser Diode
• Programmable Laser Driver Modulation Current from 5mA to 60mA
• Programmable Laser Driver Bias Current from 1mA to 100mA
• Laser Driver Enable Control
• Automatic Optical Average Power Control
• Supply Current of 80mA
• PECL Limiting Amplifier Outputs
• 48-Pin TQFP Package

APPLICATIONs
• SONET/SDH at 622Mb/s, 1.244Gb/s, 2.488Gb/s and 3.125Gb/s
• Full-Speed Fibre Channel (1.062Gb/s)