Moore-Penrose Pesudoinverse-Based Sub-Binary SAR ADC Fore-Calibration Method

This paper proposes a Moore-Penrose Pesudoinverse-based foreground calibration method on sub-binary SAR ADC to mitigate the impact of capacitor mismatch. It is developed on the Moore-Penrose pseudoinverse method in solving linear equations to estimate the bit weights of the capacitors array and offset of comparator during calibration. These coefficients are then applied to tune the original code to eliminate non-linearity caused by capacitor mismatch. Behavioral simulations on a 12-bit SAR ADC indicate that only 196 cycles of quantization are required for the proposed method to complete calibration. Monte Carlo simulation results show the signal-to-noise-and-distortion ratio (SNDR) improves from 45.4 dB to 72.2 dB and the spurious-free dynamic range (SFDR) improves from 48.3 dB to 81.8 dB after the calibration.