A 1.7 mW 11b 250 MS/s 2-Times Interleaved Fully Dynamic Pipelined SAR ADC in 40 nm Digital CMOS

Abstract

A 250 MS/s 2x interleaved 11 bit pipelined SAR ADC in 40 nm digital CMOS is presented. Each ADC channel consists of a 6b coarse SAR, a dynamic residue amplifier and a 7b fine SAR with a total of two bits of redundancy. Calibration is leveraged to adjust the uncertain gain of the chosen residue amplifier and various other non-idealities. The ADC achieves a peak SNDR of 62 dB at 10 MS/s, and 56 dB for a Nyquist input at 250 MS/s. The low frequency energy per conversion step ranges from 7 fJ at 10 MS/s to 10 fJ at 250 MS/s.