The MAX3643 compact burst mode laser driver, designed for PON (Passive Optical Network) applications, offers some customers the potential of a lower-cost system by allowing them to use already available microcontroller features (available in a physical layer controller or a MAC layer controller) to adjust the laser currents. The total driver and controller costs can be reduced by taking the laser controller circuits out of the laser driver, which is typically done on a high-speed BiPOLAR or BiCMOS process, and placing the control into a low-cost CMOS microcontroller.


This application note discusses some common techniques for digital laser control that can be incorporated into a low-cost microcontroller or an available system controller. Examples and test data are also provided, showing the typical performance of such methods.