Patent ID: 7372384
Filing Date: 2008-05-13
Classification: H03M

Abstract:
1. An analog-to-digital converter (ADC) comprising: a hybrid-type sigma-delta modulator comprising a digital delta-stage and an analog sigma-stage, wherein said analog sigma-stage comprises an analog low-pass filter adapted to only pass a low frequency audio band between approximately 0-20 khz of a pulse-width modulation (PWM) wave, and wherein said digital delta-stage comprises: a comparator attached to said hybrid-type sigma-delta modulator; a low-pass filter configured in a digital domain and adapted to receive a signal output of said comparator and remove high-frequency components of the comparator output above said audio band; a PWM back converter adapted to receive the filtered signal output and translate the digital low-pass filtered signal output to a power supply transient value in a digital format; and a dither signal source adapted to inject a dither signal to said digital delta-stage.