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:
Sep. 11, 2012
Filed:
Mar. 11, 2009
Hongbo Zhang, Shanghai, CN;
Vincent Fong, Cupertino, CA (US);
Jing Xu, Shanghai, CN;
Yuling Khang, Shanghai, CN;
Hongbo Zhang, Shanghai, CN;
Vincent Fong, Cupertino, CA (US);
Jing Xu, Shanghai, CN;
Yuling Khang, Shanghai, CN;
Abstract
In one embodiment the present invention includes a method for starting up a class D amplifier. The method comprises increasing, gating, and driving. The increasing includes increasing a duty cycle of a pulse train from a first duty cycle to a second duty cycle. The gating includes gating a signal based on the increasing of the duty cycle. The gating results in a gated signal. The driving includes driving an output signal from the gated signal to charge an output capacitor. The output capacitor is coupled to a speaker. The increasing of the duty cycle contributes to the charging of the output capacitor such that switching sounds detectable by the human ear are reduced.