A Jitter Injection Module for Production Test of 52-Gbps PAM4 Signal Interfaces

In recent high-speed data transmissions, a multilevel signaling such as a pulse amplitude modulation (PAM) is adopted instead of binary signaling to enable higher data rate. For testing PAM receivers, stressed testing which utilizes test signal with jitter and noise is very important. This paper introduces a jitter injection module for 4-level PAM (PAM4) signals. It can generate a 52-Gbps PAM4 signal from two 26-Gbps non-return-to-zero (NRZ) signals and inject jitter with frequency up to 1 GHz and amplitude up to 100 ps into the PAM4 signal. Experimental results demonstrate injecting of sinusoidal jitter, random jitter and bounded uncorrelated jitter into PAM4 signals. Combining this jitter injection module with an existing ATE provides low cost jitter tolerance testing of high-speed PAM4 signal interfaces.