Delta-sigma modulator and dithering method including a dithering capability for eliminating idle tones

Abstract

A delta-sigma modulator (100) including a dithering capability for eliminating idle tones is provided according to the invention. The delta-sigma modulator (100) includes a bitstream converter (107) configured to generate a digital signal output substantially corresponding to an analog signal input, a periodicity detector (111) coupled to the bitstream converter (107) and configured to detect periodicity in the digital signal output, and a dithering sequence generator (116) connected to and activated by the periodicity detector (111). The dithering sequence generator (116) generates a dithering sequence. The delta-sigma modulator (100) further includes a pulse-width modulation (PWM) generator (119) coupled to the dithering sequence generator (116) and receiving the dithering sequence. The PWM generator (119) modulates the dithering sequence onto the analog signal input of the delta-sigma modulator (100) as a dithering signal.

Dependencies are inferred from the claim text.