NEW MULTIBIT DELTA-SIGMA MODULATOR STRUCTURE WITH REDUCED SENSITIVITYTO THE D-A CONVERSION ERROR

A new structure is presented for multibit delta-sigma modulators, wher e the D/A conversion error as well as the A/D conversion error (the qu antisation noise) is spectrally shaped. Thus the requirement on the ac curacy of the D/A convertor is relaxed without sacrificing the advanta ges of using a multibit A/D convertor in delta-sigma modulators. The n ew structure also has a feature of design flexibility, for the choice of the noise shaping function does not have strong influence on the si gnal in the passband. Both analysis and simulation show that the new s tructure is relatively tolerant of analogue component inaccuracies.