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:
Jul. 23, 2013
Filed:
May. 10, 2011
Yung-hsiang Yang, Hsinchu, TW;
Yu-nan Yen, Zhudong Township, Hsinchu County, TW;
Yung-Hsiang Yang, Hsinchu, TW;
Yu-Nan Yen, Zhudong Township, Hsinchu County, TW;
Raydium Semiconductor Corporation, Hsinchu County, TW;
Abstract
A control circuit applied in a light emitting diode (LED) driver includes a counter, a sample circuit, and a signal source. The counter counts a parameter indicating the duty cycle width of a dimming signal in response to a front edge of the dimming signal. The sample circuit obtains a sample signal by means of sampling the most significant bit (MSB) of the parameter in response to the rear edge of the dimming signal. The duty cycle width is determined to be greater than a threshold value and smaller than that when the sample signal corresponds with a terminal value and an initial value, respectively. The signal source provides a reference voltage corresponding to first level and that corresponding to second level, higher than the first level, to drive a boost converter of the LED driver in response to the terminal value and the initial value, respectively.