The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 24, 2007
Filed:
Dec. 12, 2003
Kazunobu Ohkuri, Kanagawa, JP;
Toshihiko Masuda, Tokyo, JP;
Kazunobu Ohkuri, Kanagawa, JP;
Toshihiko Masuda, Tokyo, JP;
Sony Corporation, Tokyo, JP;
Abstract
In an audio amplifier having a D-class power amplifier, a noise upon muting is suppressed. A sampling rate converter circuit for sampling rate converting a digital audio signal into a digital audio signal, and a ΔΣ modulation circuit for re-quantizing the digital audio signal into a bit-reduced digital audio signal are provided. Further, a PWM modulation circuit for converting the digital audio signal into a PWM signal, and a D-class power amplifier to which the PWM signal are supplied. Still further, a dither signal forming circuit for superimposing a dither signal SDI on the digital audio signal, and a forming circuit for forming a muting signal SDET are provided. Upon muting, an input side of the sampling rate converter circuit is stopped by the muting signal SDET.