A 12-bit Fully Differential SARADC with a Novel Capacitor Mismatch Calibration

This paper presents a fully differential 12-bit SAR ADC with a novel capacitor mismatch calibration. The calibration calculates the capacitor mismatch via the metastability of the comparator and statistical method. A novel metastability detection circuit is designed to ensure the detection accuracy and avoid the “fake metastability” problem. Post-simulation shows that the ENOB is improved by 1.52 bits to achieve 11.71 bits at 130MSps sampling rate using the proposed calibration algorithm.