A Self-Calibrated Sampling Noise Cancellation Technique for Noise-Shaping SAR ADC

The sampling noise cancellation (SNC) technique has been applied to noise-shaping SAR (NS-SAR) ADCs to reduce the sampling capacitance, which makes the ADCs more easy-driven. However, the traditional SNC technique limited its applications by the PVT-sensitive noise cancellation ratio and hence noise performance. This paper proposes a new SNC technique with self-calibrated PVT-robust noise-cancellation ratio. The error of the noise-cancellation ratio (NCR) is detected and calibrated in background without any external dither or test signal. Simulation results show that the proposed SNC technique achieves more PVT-stable NCR over a traditional SNC scheme.