Data Path Nonlinearity Estimation for 200 Gbps PAM4 Serdes Receivers

Abstract

This paper presents a method to estimate the nonlinearity of the analog data path of Serdes receiver, in real time operation. The estimated nonlinearity can be used to adapt various receiver parameters to improve performance. The proposed method is demonstrated for a 200 Gbps ADC-Based receiver, in which, nonlinearity estimate is used to set Analog Front End (AFE) swing optimally, resulting in improved eye opening. The proposed method is also used to adapt decompressive characteristic optimally.

Keywords

• Serdes
• nonlinearity
• continuous time linear equalizer
• variable gain amplifier
• decision feedback equalization
• feed forward equalization