Patent ID: 6320526
Filing Date: 2001-11-20
Classification: H03M

Abstract:
A sigma-delta (.SIGMA..DELTA.) analog/digital converter with adaptive dither comprising:an analog-to-digital modulator for generating a digital signal based upon an analog input signal;a comparator for detecting an amplitude of the analog input signal; anda dithering circuit for generating and injecting a dithering signal to the analog-to-digital modulator, the dithering signal having an amplitude adaptively regulated as a function of the amplitude of the analog input signal detected by the comparator, the dithering signal having a spectrum similar to white noise, said dithering circuit comprisinga digital generator for generating a digital white noise signal,at least one digital divider connected to an output of the digital generator for dividing the digital white noise signal,a path selector having an input connected to the output of the digital generator, at least a second input connected to an output of the digital divider, and a selection input connected to an output of the comparator,a digital/analog converter connected to the path selector, anda filter, of at least a second-order, for filtering the dithering signal.