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. 14, 2015
Filed:
Jul. 13, 2012
Xinli Peng, Chandler, AZ (US);
Troy Stockstad, Chandler, AZ (US);
Ricardo T. Goncalves, Chandler, AZ (US);
Xinli Peng, Chandler, AZ (US);
Troy Stockstad, Chandler, AZ (US);
Ricardo T. Goncalves, Chandler, AZ (US);
QUALCOMM Incorporated, San Diego, CA (US);
Abstract
A method and apparatus for derating current and for derating current for a camera flash. The method comprises monitoring a local junction temperature of a module. The local junction temperature is converted into a local junction current. The local junction current is then compared with a reference current, which is independent of temperature. After the current comparison and subtraction is made, a derate control current is obtained to generate the LED reference current. After the temperature crosses the temperature threshold, the derate control current is derated. Both the temperature threshold and current derate slope are programmable and precisely controlled. The LED output current is regulated and proportional to the LED reference current. If the local junction temperature is greater than the temperature threshold, the LED output current is derated at the moment of the camera flash to avoid thermal overload.