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.

Date of Patent:
Feb. 16, 2016

Filed:

Mar. 14, 2013
Applicant:

Analog Devices, Inc., Norwood, MA (US);

Inventor:

Jonathan Kraft, Frederick, CO (US);

Assignee:

Analog Devices, Inc., Norwood, MA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 37/00 (2006.01); H05B 33/08 (2006.01); H05B 37/02 (2006.01);
U.S. Cl.
CPC ...
H05B 33/0809 (2013.01); H05B 33/0815 (2013.01); H05B 33/0827 (2013.01); H05B 33/0836 (2013.01); H05B 33/0884 (2013.01); H05B 37/02 (2013.01); Y02B 20/341 (2013.01); Y02B 20/347 (2013.01);
Abstract

A LED drive system for controlling an off-chip power supply enables the power supply function to be located 'off-chip'—i.e., on an IC which is separate from the IC containing the other LED drive system components. The off-chip supply provides a common line voltage for LED strings connected in series with respective current sink circuits at respective junctions, in response to a signal applied to a control input. The system includes a 'minimum' circuit which outputs the least of the voltages at the junctions, and an I/O pin which receives a signal that varies with the output of the minimum circuit. When the external supply's control input is coupled to the system's I/O pin, the present system controls the output of the external power supply as needed to provide a desired common line voltage.


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