METHOD FOR IMPROVING THE RESOLUTION AND THE CORRECTION OF DISTORTIONS IN A SIGMA-DELTA MODULATOR, AND SIGMA-DELTA MODULATOR IMPLEMENTING SAID METHOD

摘要

The invention relates to a method for improving the resolution and the correction of distortions in a sigma-delta modulator, wherein the modulator (200) converts an analog input signal e(t) into a secondary output digital signal s(t) sampled at a frequency f? and encoded over NB bits, a second main output digital signal s'(t) represented over NMSB bits being also available at the output. At least three forms of processing are sequentially applied to the two outputs, the first form of processing (201) comprising a demodulation by a frequency f0 and an N-factor decimation (202, 203) in an independent manner, the second form of processing (204) comprising an improvement of the resolution and the third form of processing (208) comprising a correction of the distortions, the three forms of processing being carried out after decimation. The invention also relates to a sigma-delta modulator implementing the method of the invention.