A 29mW 5GS/s Time-interleaved SAR ADC achieving 48.5dB SNDR With Fully-Digital Timing-Skew Calibration Based on Digital-Mixing

Abstract

This paper presents a 5GS/s 16-way Time-Interleaved SAR ADC in 28nm CMOS, proposing a fully-digital background timing-skew calibration based on digital mixing, without adding any extra analog circuits. We implement the sub-channel SAR with a splitting-combined monotonic switching procedure. The prototype ADC achieves 48.5dB SNDR at Nyquist rate, while the power consumption is 29mW leading to a Walden FOM of 26.7fJ/conv-step.