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:
Dec. 08, 2009
Filed:
Mar. 17, 2008
Kuan-jen Tseng, Sinshih Township, Tainan County, TW;
Po-yu LI, Sinshih Township, Tainan County, TW;
Kuan-Jen Tseng, Sinshih Township, Tainan County, TW;
Po-Yu Li, Sinshih Township, Tainan County, TW;
Himax Analogic, Inc., , TW;
Abstract
A class D audio amplifier includes an error amplifier, a comparator, a bridge circuit, a feedback circuit and a silent start circuit. The error amplifier generates an error signal by amplifying a difference between a feedback signal and an audio input signal. The comparator generates a first pulse width modulation (PWM) signal by comparing a first triangular-wave signal and the error signal. The bridge circuit has switches alternately conducting a current flowing into and from a load. The feedback circuit generates the feedback signal indicating a condition of the load. The silent start circuit performs AND operation of the first PWM signal and a second PWM signal having a gradually increased duty ratio to generate a third PWM signal for control of the switches of the bridge circuit.