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. 25, 2012
Filed:
May. 04, 2011
Yung Lin Lin, Palo Alto, CA (US);
Ching Chuan Kuo, Taipei, TW;
Tiesheng Yan, Chengdu, CN;
Xinhe Su, Chengdu, CN;
Yung Lin Lin, Palo Alto, CA (US);
Ching Chuan Kuo, Taipei, TW;
Tiesheng Yan, Chengdu, CN;
Xinhe Su, Chengdu, CN;
O2Micro, Inc., Santa Clara, CA (US);
Abstract
A controller for controlling dimming of a light-emitting diode (LED) light source provides a pulse signal by comparing a sensing signal indicative of a current flowing through the LED light source to a reference signal. The controller controls the current through the LED light source according to the pulse signal during a first state of a pulse-width modulation signal and cutting off the current through the LED light source during a second state of the pulse-width modulation signal. The controller receives a dimming request signal indicative of an operation of a power switch coupled between an AC power source and a bridge rectifier and adjusts both a level of the reference signal and a duty cycle of the pulse-width modulation signal based on the dimming request signal.