2.7Gbps, +3.3V DC-Coupled Laser Driver

The MAX3850 is a +3.3V DC-coupled laser driver for SDH/SONET applications up to 2.7Gbps. The device accepts differential data and clock inputs and provides bias and modulation currents for driving a laser. If a clock signal is available, a synchronizing input latch can be used to reduce jitter. An automatic power-control (APC) feedback loop is incorporated to maintain a constant average optical power over temperature and lifetime. The wide modulation current range of 5mA to 60mA (up to 80mA AC-coupled) and bias current of 1mA to 100mA are easy to program, making this product ideal for SDH/SONET applications. The MAX3850 also provides laser current-enable control, two current monitors that are directly proportional to the laser bias and modulation currents, and a failure-monitor output to indicate when the APC loop is unable to maintain the average optical power. Designed to be DC-coupled to the laser with a supply voltage of only 3.3V, the MAX3850 greatly simplifies interface requirements. The MAX3850 is available in a small 32-pin QFN package as well as dice.

Applications

* Add/Drop Multiplexers * Digital Cross-Connects * MPLS Transmitter Systems * SDH/SONET Transmission Systems * Section Regenerators

* Single +3.3V Power Supply

* 35mA Supply Current

* Programmable Bias Current from 1mA to 100mA

* Programmable Modulation Current from 5mA to 60mA (Up to 80mA AC-Coupled)

* Bias Current and Modulation Current Monitors

* 70ps Rise/Fall Time

* Automatic Average Power Control with Failure Monitor

* Complies with ANSI, ITU, and Bellcore SDH/SONET Specifications

* Laser Current-Enable Control