Abstract: A sigma-delta modulator. The sigma-delta modulator comprises a summer, a loop filter, a quantizer, a D/A converter and a dynamic element matching logic. The summer receives an analog input signal and a feedback signal to generate an error signal to the loop filter which generates a filtered signal to the quantizer, thereby converting the filtered signal to a quantized output signal to the D/A converter including D/A elements and generating the feedback signal corresponding to selected D/A elements thereof. The dynamic element matching logic coupled between the quantizer and D/A converter selects the D/A elements of the D/A converter, wherein it divides the D/A elements into groups, where the number of the groups is prime to that of the D/A elements, and then selects the groups and D/A elements thereof according to the quantized output signal and the previous selection of groups and D/A elements.

Abstract: A sigma-delta modulator comprises a summer, a loop filter, a quantizer, a D/A converter and a dynamic element matching logic. The summer receives an analog input signal and a feedback signal to generate an error signal to the loop filter which generates a filtered signal to the quantizer, thereby converting the filtered signal to a quantized output signal to the D/A converter including first and second converting elements which together form a plurality of D/A elements and generating the feedback signal. The dynamic element matching logic selects the D/A elements and determines the number of groups into which the D/A elements are divided, where the number of the groups is prime to that of the first converting elements, distributes the D/A elements to each group equally, and selects the groups and D/A elements thereof according to the quantized output signal and the previous selection of groups and D/A elements.

Abstract: A D/A converter. The D/A converter comprises a R-2R ladder network and a correction circuit. The R-2R ladder network receives first and second reference voltage terminals and generates an analog voltage at an output terminal in response to a digital input code. The correction circuit, coupled between the first and second reference voltage terminals via a first switch and a second switch respectively, comprises a plurality of R resistors wherein a terminal of one of the R resistors thereof is coupled to the output terminal via a third switch, and the first, second and third switches are turned on in response to the input digital code.