Dynamic element matching digital/analog conversion system and sigma-delta modulator using the same

摘要

A dynamic element matching sigma-delta modulator includes an adder to receive an analog input signal and a feedback signal to generate an error signal; a loop filter to generate a filtered signal according to the error signal; a quantizer to change the filtered signal into a quantized output signal; a digital/analog converter (DAC) having a plurality of digital/analog elements to generate the feedback signal corresponding to the quantized output signal; and a dynamic element matching device to receive the quantized output signal to accordingly set an element of the DAC to be a previous non-participant element and the other elements to be previous participant elements, and reselects participant elements according to the quantized output signal and the previous participant elements for further generating the feedback signal corresponding to the quantized output signal.