Sony Corporation

Arihiro Moroboshi

Yusuke Yamamoto

Toshihiko Masuda

A digital amplifier apparatus includes a gain-adjusting section operable to adjust a gain of a digital audio signal; a dither-superposing section operable to superpose a predetermined dither on the digital audio signal; a pulse-width-modulated signal generating section operable to generate a pulse-width-modulated signal corresponding to the digital audio signal; an amplifying section operable to cause a switching element to perform a switching operation in accordance with the pulse-width-modulated signal; a pulse-width changing section operable to change a ratio between a 'high' state and a 'low' state of the pulse-width modulated signal; a synchronizing section operable to synchronize the pulse-width modulated signal with a reset signal that resets the digital audio signal; and a control section operable to perform a resetting operation by setting the gain of the digital audio signal to a zero level upon receiving the reset signal, stopping the superposing of the dither to thereby generate the pulse-width modulated signal, and setting the pulse-width modulated signal to the &#x201c;low&#x201d; state by using the pulse-width modulated signal synchronized with the reset signal, thereby causing the switching element to stop performing the switching operation.

Digital amplifier apparatus and method of resetting a digital amplifier apparatus

A digital amplifier apparatus includes a gain-adjusting section operable to adjust a gain of a digital audio signal; a dither-superposing section operable to superpose a predetermined dither on the digital audio signal; a pulse-width-modulated signal generating section operable to generate a pulse-width-modulated signal corresponding to the digital audio signal; an amplifying section operable to cause a switching element to perform a switching operation in accordance with the pulse-width-modulated signal; a pulse-width changing section operable to change a ratio between a 'high' state and a 'low' state of the pulse-width modulated signal; and a control section operable to perform a muting process by causing the gain-adjusting section to set the gain of the digital audio signal to a zero level, the dither-superposing section to stop superposing the dither, and the pulse-width changing section to change, step by step, the ratio between the &#x201c;high&#x201d; state and the &#x201c;low&#x201d; state of the pulse-width modulated signal toward the &#x201c;low&#x201d; state upon receipt of a predetermined muting signal for muting the digital audio signal, thereby maintaining the &#x201c;low&#x201d; state and stopping the switching operation performed in accordance with the pulse-width modulated signal.

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Tokyo, Japan

Arihiro Moroboshi