Patent Number: 7,733,034

Title: Single inductor serial-parallel LED driver

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.

Inventors: Kotikalapoodi; Sridhar V. (Santa Clara, CA), Zeng; James (Cupertino, CA), Szabo; Tivadar (Santa Clara, CA), Pandyn; Manisha P. (Anaheim Hills, CA), Roohparvar; Farzan (Monte Sereno, CA)

Assignee: Broadcom Corporation

International Classification: G05F 1/00 (20060101); H05B 37/00 (20060101)

Expiration Date: 2022-06-08 0:00:00