Post-Compensation of a CT First Order Sigma-Delta ADC Using PWL Dynamic Systems

Abstract

An approach for compensating non-linearities in a continuous-time first-order sigma-delta converter with one bit quantization is presented. The proposed compensators are parallel nonlinear dynamic systems using piecewise linear static functions. A reduction of an order of magnitude is obtained in the measured squared error when compared to the uncompensated sigma-delta converter. Our results confirm a significant improvement in signal to noise and distortion ratio for single tone input signals and in spurious free dynamic range for multi-tone inputs.