Patent ID: 7982648

Claim:
A dynamic element matching sigma-delta modulator comprising: an adder, for generating an error signal based on a difference between a analog input signal and a feedback signal; a loop filter, connected to the adder for receiving the error signal to generate a filtered signal; a quantizer, connected to the loop filter for changing the filtered signal into a quantized output signal; a digital/analog converter (DAC), connected to the adder and having a plurality of digital/analog elements, for generating the feedback signal to the adder; and a dynamic element matching device, connected between the quantizer and the DAC, for receiving the quantized output signal to select the digital/analog elements from the DAC; wherein the dynamic element matching device sets one of the digital/analog elements to be a first non-participant element and the others of the digital/analog elements to be participant elements, and reselects participant elements according to the quantized output signal and the participant elements for further generating the feedback signal corresponding to the quantized output signal, wherein the dynamic element matching device resets one of the participant elements to be a second non-participant element and the first non-participant element to be a participant element when the quantized output signal is a predetermined signal, and wherein the predetermined signal is a maximum of the quantized output signal.