A Noise Shaping SAR ADC with kT/C Noise Cancellation and Mismatch Error Shaping

The resolution of SAR ADCs is primarily limited by sampling noise, DAC mismatch, and comparator noise. This work presents a noise-shaping SAR ADC design that addresses all these error sources. Sampling noise is mitigated using a kT/C noise cancellation technique combined with resampling. DAC mismatch is managed through data-weighted averaging (DWA) and mismatch error shaping (MES), while comparator noise is reduced using a second-order passive noise-shaping (NS) technique. Designed in a 28nm CMOS process, the ADC achieves 86.8 dB SNDR across a 2.8 MHz bandwidth with a power consumption of 3.8 mW.