Patent ID: 7492218

Claim:
A digital amplifier apparatus, comprising: gain-adjusting means for adjusting a gain of a digital audio signal; dither-superposing means for superposing a predetermined dither on the digital audio signal; pulse-width-modulated signal generating means for generating a pulse-width-modulated signal corresponding to the digital audio signal; amplifying means for causing a switching element to perform a switching operation for amplification in accordance with the pulse-width-modulated signal; pulse-width changing means for changing a ratio between a “high” state and a “low” state of the pulse-width modulated signal; synchronizing means for synchronizing the pulse-width modulated signal with a reset signal that resets the digital audio signal; and control means for performing a resetting operation by setting the gain of the digital audio signal to a zero level upon receiving the reset signal, for stopping the superposing of the dither to thereby generate the pulse-width modulated signal, and for setting the pulse-width modulated signal to the “low” state by using the pulse-width modulated signal synchronized with the reset signal, thereby causing the switching element to stop performing the switching operation.