Digital mixer and volume control for AC'97 multimedia audio codec

摘要

Audio Codec '97 (AC'97) is emerging as a new standard for multimedia PC audio codecs.Traditionally PC audio codec devicescontain large and complex analog circuitry,especially for adjusting the gain/attenuation of input signals and mixing them together.This paper suggests moving these analog functional blocks to digital domain.The main point is to process signals in the oversampled digital domain.THis oversampled bistream signal processing has several benefits over both analog and traditional and well known digital signal processing mehtods.The bitstream signal processingsolution presented is shown to have better than 90 dB S/N and THD performance over audio band.Also digital filtering and other one-bit bitstream digital signal porcessing applciations are briefly discussed.