Techniques for improving mismatch shaping of dynamic element matching circuit within delta-sigma modulator

摘要

A delta-sigma modulator includes a receiving circuit, a loop filter, a quantizer, a dynamic element matching circuit and a digital to analog converter. The receiving circuit is arranged for receiving a feedback signal and an input signal to generate a summation signal. The loop filter is arranged for receiving the summation signal to generate a filtered summation signal. The quantizer is arranged for generating a digital output signal according to the filtered summation signal. The dynamic element matching circuit is arranged for receiving the digital output signal to generate a shaped digital output signal for shaping element mismatch. The digital to analog converter is arranged for performing a digital to analog converting operation upon a signal derived from the shaped digital output signal to generate the feedback signal to the receiving circuit, wherein clock signals used by the quantizer and the dynamic element matching circuit have different frequencies.