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. 19, 2011
Filed:
Jun. 30, 2008
Yuhui Chen, Fremont, CA (US);
Junjie Zheng, Santa Clara, CA (US);
John William Kesterson, San Jose, CA (US);
Yuhui Chen, Fremont, CA (US);
Junjie Zheng, Santa Clara, CA (US);
John William Kesterson, San Jose, CA (US);
iWatt Inc., Los Gatos, CA (US);
Abstract
An LED driver includes at least two interlocked closed feedback loops. One feedback loop controls the duty cycle of the on/off times of a switch connected in series to the LED string, and the other feedback loop controls the duty cycle of the on/off times of a power switch in the switching power converter that provides a DC voltage applied to the LED string. The LED driver of the present invention achieves fast control of the LED brightness and current sharing among multiple LED strings simultaneously in a power-efficient and cost-efficient manner.