A 32-GS/s Front-End Sampling Circuit Achieving ＞39 dB SNDR for Time-Interleaved ADCs in 65-nm CMOS

摘要

This paper presents a 32-GS/s front-end sampling circuit (FESC) in 65-nm CMOS. The FESC is designed for a 32-channel time-interleaved analog-to-digital converter (ADC), and the 4 x 8 two-stage interleaving structure leads to a good trade-off between bandwidth and linearity. The analysis and cancellation of charge injection, clock feedthrough, and signal feedthrough are presented. Inductor peaking technique is adopted to extend the bandwidth of the buffer between the first and the second stage. Based on the simulation results, the proposed FESC consumes 136 mW at 32 GS/s, and the signal-to-noise ratio (SNDR) is up to 39.55 dB at Nyquist input, achieving a state-of-the-art power efficiency.