A Single Channel Bandpass SAR ADC with Digitally Assisted NTF Re-configuration

Abstract

A single channel band-pass (BP) SAR ADC has been presented in this work. The proposed ADC uses a maximum likelihood estimator (MLE) to estimate the SAR residue similar to a two-stage architecture. The ADC output is obtained by subtracting a delayed version of the MLE estimate from the SAR output thus generating a noise transfer function (NTF) which can be re-configured by changing the delay. A 65nm BP ADC prototype achieves a 67.8dB SNDR when clocked at 2MS/s over a 79kHz bandwidth. The ADC consumes 13µW from a 1V supply leading to a 166dB schreier FoM.