The MAX3643 burst-mode laser driver provides bias and modulation current drive for PON burst-mode ONT applications. It is specifically designed for use with a low-cost external controller for the APC (and if desired, AMC) loop. A high-speed differential burst-enable input enables the driver to switch the laser from a dark (output off) condition to full on-condition in less than 2ns. When BEN is inactive, typical modulation and bias currents are 5A each. Laser modulation current can be set from 10mA to 85mA and bias current can be set from 1mA to 70mA using the MODSET and BIASSET inputs. A sample-and-hold circuit is provided to capture the monitor diode output during short PON bursts, if needed, and the BEN high-speed signal is mirrored on an LVCMOS output to be used by the controller operating the APC/AMC loop.