ISI Injection Filter Designs Using PIN and Varactor Diodes for SerDes Testing on ATE

This paper presents two ISI injection filter designs using PIN diodes, varactor diodes, fixed inductors, and transmission line inductance for SerDes device testing. Simulation results show that the combination of the simple single stage filter and the complex 3-stage filter can emulate transmission lines up to 90 inch long from 1Gbps to 6.4Gbps. Eye diagram measurement results show that the simple filter can work as a fine tune ISI injection filter or a baseline with minimum ISI for higher bit rates, while the complex filter can close eye up to 28% UI at 1Gbps and up to 100% UI at a bit rate of 6.4Gbps