A 6-bit 10-GS/s 63-mW 4x TI time-domain interpolating flash ADC in 65-nm CMOS

Abstract

A 6-b 4x time-interleaved (TI) time-domain interpolating flash ADC is presented for high-speed applications. The dynamic-amplifier-structured voltage-to-time converter (VTC) enables linear zero-crossing interpolation in the time-domain with an interpolation factor of eight, resulting in reduced power consumption and area. A sequential slope-matching offset calibration scheme is proposed not only for VTC offset but also for interpolated zero-crossing accuracy. The prototype 6-bit 10-Gs/s 4x TI flash ADC was implemented in a 65-nm CMOS process and occupied 0.22 mm2 including a 4-to-1 output MUX and 243-times output decimator. The ADC achieves SNDR of 28.9 dB at Nyquist input and a total power consumption of 63 mW under supplies of 0.85 V and 1.1 V for the ADC cores and clock generator + T/Hs, respectively.