MAX3656: Optimizing the MAX3656 Output Network for Long Laser Leads in GPON/GEPON Application


The MAX3656 is designed for burst-mode laser driver operation in various ONT/ONU PON applications. The majority of optical subassemblies used in these applications come with leaded signal connections. It is common to mount the optical devices to the top of the PCB and bend the pins down to the PCB making trough-hole connections. While this type of assembly is often chosen for cost and manufacturing reasons, the long leads of the connection can have a severe impact on the signal quality at gigabit data rates. This application note discusses the impact of the increased inductance in more detail and illustrates by simulation and lab measurements a compensation network that provides excellent gigabit operation with large amounts of lead inductance.