The MAX3867 is a complete, single +3.3V laser driver for SDH/SONET applications up to 2.5Gbps. The device accepts differential PECL data and clock inputs and provides bias and modulation currents for driving a laser. The synchronizing input latch can be bypassed if a clock signal is not available. 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 and bias current of 1mA to 100mA are easy to program, making this product ideal for use in various SDH/SONET applications. The MAX3867 also provides enable control, a programmable slow-start circuit to set the laser turn-on delay, and a failure-monitor output to indicate when the APC loop is unable to maintain the average optical power. The MAX3867 is available in a small 48-pin TQFP package as well as dice.