D/A CONVERTER CIRCUIT AND DIGITAL INPUT CLASS-D AMPLIFIER

摘要

PURPOSE: A D/A converter circuit and a digital input class-D amplifier are provided to prevent a dither signal component in an analog signal using an adding operation of an analog adding unit. CONSTITUTION: A ΔΣ modulator(501) ΔΣ-modulates an input digital audio signal. A DEM decoder(502) outputs a plurality of time series digital signals with 1 or 0 density according to a digital signal supplied from the ΔΣ modulator. An analog adding unit(503) converts the inversion dither signal and the time series digital signal of the DEM decoder into an analog signal. An analog signal processor(504) processes the analog signal of the analog adding unit. A dither signal generator(505) outputs the dither signal and the inversion dither signal that are AC signals.