Distortion measurement for limiting jitter in PAM transmitters

摘要

Methods and test equipment for measuring jitter in a Pulse Amplitude Modulated (PAM) transmitter. Under one procedure, a first two-level PAM signal test pattern is used to measure clock-related jitter separated into random and deterministic components, while a second two-level PAM signal test pattern is used to measure even-odd jitter (EOJ). Under another procedure, A four-level PAM signal test pattern is used to measure jitter-induced noise using distortion analysis. Test equipment are also disclosed for implementing various aspects of the test methods.

主权项

1. A method for measuring jitter in a four-level Pulse Amplitude Modulated (PAM4) transmitter, comprising:
employing a first two-level PAM4 signal test pattern to measure clock-related jitter separated into random and deterministic components; and employing a second two-level PAM4 signal test pattern to measure even-odd jitter (EOJ), wherein the first two-level PAM4 signal test pattern comprises a ‘03’ pattern that is periodical at 2 unit intervals (UI), wherein the 0 and 3 respectively correspond to a lowest and highest signal level of a PAM4 signal.