Chip Launches First 3.2-Gb/s Laser Driver

Targeted at next-generation 10-Gb/s Ethernet, SONET/SDH OC-48, Fibre Channel and DWDM equipment, the VSC7928 chip is said to represent the industry's only 3.2-Gb/s diode laser driver. With its maximum modulation current of 100 mA, the IC reportedly can be matched to a wide variety of laser diodes. Through use of an on-chip selectable data reclocking technique, the laser driver offers a simple way to achieve margin in the data eye by reducing jitter in the input data stream. And short rise and fall times are said to deliver the best dispersion penalty for short- and intermediate-reach, as well as long-reach fiber communications.
In addition, the VSC7928's low power dissipation (400 mW) makes possible the use of four of the chips to implement Coarse Wavelength Division Multiplexing (CWDM) or quad modules for the 10-Gb/s Ethernet market. Other features of the 5V device include ECL-compatible clock and data inputs, on-chip mux for clocked and non-clocked applications, direct access to modulation and bias FETs, and on-chip 50 ohm input termination for both clock and data. The VSC7928 laser diode driver comes in 32-pin TQFPs, 24-pin QFP metal-glass packages, and as dice, with the former costing less than $30 each/10,000.