Digital audio amplifier, an audio system including the same, and a method of amplifying an audio signal

摘要

A digital audio amplifier, an audio system including the same and a method of amplifying an audio signal that can reduce switching noise interference generated in a pulse width modulator are provided. The digital audio amplifier includes a selection circuit, a digital signal processor and a pulse width modulator. The selection circuit selects one of an audio data signal and a digitized broadcasting signal to output a digital input signal. The digital signal processor samples the digital input signal using one of a plurality of oversampling frequencies based on a local oscillator output signal and a separation signal to output a sampled digital signal. The pulse width modulator performs a pulse width modulation on the sampled digital signal.