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:
Jun. 08, 2010
Filed:
Apr. 24, 2007
Sridhar V. Kotikalapoodi, Santa Clara, CA (US);
James Zeng, Cupertino, CA (US);
Tivadar Szabo, Santa Clara, CA (US);
Manisha P. Pandyn, Anaheim Hills, CA (US);
Farzan Roohparvar, Monte Sereno, CA (US);
Sridhar V. Kotikalapoodi, Santa Clara, CA (US);
James Zeng, Cupertino, CA (US);
Tivadar Szabo, Santa Clara, CA (US);
Manisha P. Pandyn, Anaheim Hills, CA (US);
Farzan Roohparvar, Monte Sereno, CA (US);
Broadcom Corporation, Irvine, CA (US);
Abstract
An LED driver circuit is disclosed that can drive a plurality of LED strings that are arranged in parallel, each LED string having a plurality of component LEDs that are series-connected. The LED strings can be the same type of LEDs in each string, or have different types of LEDs from one string to another. The LED driver includes a voltage control loop that dynamically regulates the output voltage across the parallel arrangement of LED strings. The output voltage is dynamically adjusted to accommodate the LED string with the largest operational voltage drop. This enables LED displays to constructed using different types of LEDs strings, but still supply the LED strings in a power efficient manner. Further, each LED string also includes its own individual current regulation loop so that the current, and therefore brightness, of each LED string can be individually adjusted.