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. 26, 2008
Filed:
Aug. 03, 2007
Johan Tjeerd Strydom, Santa Clara, CA (US);
Jun Honda, El Segundo, CA (US);
Johan Tjeerd Strydom, Santa Clara, CA (US);
Jun Honda, El Segundo, CA (US);
International Rectifier Corporation, El Segundo, CA (US);
Abstract
A method of minimizing an audible click noise from a speaker in a Class D audio power amplifier upon shutdown or startup of a switching stage having two switches series connected at a node, the speaker being connected to the node via an output filter comprising an inductor and a capacitor, the switches being controlled by a controller. The method including the steps of determining a timing interval at the node to transition a peak voltage of the capacitor, the capacitor voltage being a speaker voltage; and eliminating the audible transient voltage excursion across the speaker that causes a click noise during the timing interval, wherein at startup ON and OFF times of the switches are incrementally increased from zero to a normal mode and at shutdown the ON OFF times of the switches are incrementally decreased from the normal mode to zero.