+3.3V, 622Mbps SDH/SONET laser driver with current monitor and APC

     The MAX3669 is a complete +3.3V laser driver with automatic Power control (APC) circuitry for SDH/SONET applications up to 622Mbps. It accepts differential PECL inputs, provides bias and modulated currents, and operates in the temperature range from -40°C to +85°C. An APC feedback loop is used to maintain constant average optical power over temperature and lifetime ranges.

     With modulation currents ranging from 5mA to 75mA and bias currents from 1mA to 80mA, it is easy to program, making this product ideal for use in a variety of SDH/SONET applications. Two pins are provided to monitor the current level in the laser :BIASMON is proportional to the laser bias current and MODMON is proportional to the laser modulated current.

     The MAX3669 also provides enable control and fault monitor output to indicate that the APC loop is unable to maintain average optical power. The MAX3669 is available in a 4mm x 4mm 24-pin thin QFN and a 5mm x 5mm 32-pin TQFP package.