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. 15, 2014
Filed:
Feb. 10, 2012
Tiesheng Yan, Chengdu, CN;
Ching-chuan Kuo, Taipei, TW;
Feng Lin, Chengdu, CN;
Jianping Xu, Chengdu, CN;
Tiesheng Yan, Chengdu, CN;
Ching-Chuan Kuo, Taipei, TW;
Feng Lin, Chengdu, CN;
Jianping Xu, Chengdu, CN;
O2Micro, Inc., Santa Clara, CA (US);
Abstract
A circuit for driving a light-emitting diode (LED) light source includes a converter, a saw-tooth signal generator, and a controller. The converter includes a switch which is controlled by a driving signal. The converter provides a sense signal indicating the current through said LED light source. The saw-tooth signal generator generates a saw-tooth signal based on the driving signal. The controller generates the driving signal based on signals including the saw-tooth signal and the first sense signal to adjust the current through the LED light source to a target level and to correct a power factor of the driving circuit by controlling an average current of the input current to be substantially in phase with said input voltage.