Design and Comparison of Three 20-Gb/s Backplane Transceivers for Duobinary, PAM4, and NRZ Data

A full study of three data formats including duobinary, PAM4, and NRZ is proposed to estimate the performance of the corresponding transceivers under different conditions. Transceiver prototypes designed and optimized for the three signalings are presented to evaluate their performance as well as the feasibility. The three transceivers have been tested thoroughly in Rogers and FR4 boards. Fabricated in 90-nm CMOS technology, all three transceivers achieve error-free operation with 20-Gb/s 2
³¹
-1 PRBS data over 40-cm Rogers and 10-cm FR4 channels. General comparison reveals that the NRZ data still achieves the best performance at 20 Gb/s.