AUDIO SIGNAL PROCESSING CIRCUIT, AUDIO SIGNAL PROCESSING METHOD, AND ON-VEHICLE AUDIO APPARATUS, AUDIO COMPONENT APPARATUS AND ELECTRONIC APPARATUS USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an audio signal processing circuit that has analog amplifiers and a DSP integrated together while keeping sound quality intact.SOLUTION: A first amplifier AMP1 non-inversely amplifies an input audio signal S. A second amplifier AMP2 inversely amplifies an output signal S1 of the first amplifier AMP1. An analog/digital converter 10 is of a differential input type, and receives the output signal S1 of the first amplifier AMP1 at a positive input terminal thereof and receives an output signal S2 of the second amplifier AMP2 at a negative input terminal thereof. A digital/analog converter 14 outputs a third, differential analog audio signal S3. A third amplifier AMP3 inverts a positive signal S3p of the third analog audio signal S3 and adds it to a negative signal S3n thereof to generate a fourth, single-ended analog audio signal S4. A fourth amplifier AMP4 inversely amplifies the fourth analog audio signal S4 to generate an output audio signal S.