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:
Aug. 24, 2021
Filed:
Dec. 19, 2019
Applicant:
Yamaha Corporation, Hamamatsu, JP;
Inventor:
Takeshi Togawa, Anjo, JP;
Assignee:
Yamaha Corporation, Hamamatsu, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03F 3/21 (2006.01); H04R 3/04 (2006.01); H03F 3/217 (2006.01);
U.S. Cl.
CPC ...
H03F 3/2175 (2013.01); H04R 3/04 (2013.01); H03F 2200/03 (2013.01); H03F 2200/171 (2013.01);
Abstract
An amplifying device includes a self-excited class D amplifier circuit and a band elimination filter. The self-excited class D amplifier circuit includes a modulation circuit that is configured to apply self-oscillating pulse modulation to an audio signal. The modulation circuit is configured to receive, from a signal generation circuit, a supply of a synchronizing signal with which the self-oscillation synchronizes. The band elimination filter is configured to reduce components that belong to a frequency band including a frequency of the synchronizing signal, in an output signal from the self-excited class D amplifier circuit.