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:
Mar. 12, 2013
Filed:
Oct. 05, 2010
Karl Richard Volk, Scotts Valley, CA (US);
Thomas Joseph Karpus, Cary, NC (US);
David Paul Keesor, Chapel Hill, NC (US);
Russell Coleman Deans, Chapel Hill, NC (US);
Paul Edward Hinson, Carrboro, NC (US);
Karl Richard Volk, Scotts Valley, CA (US);
Thomas Joseph Karpus, Cary, NC (US);
David Paul Keesor, Chapel Hill, NC (US);
Russell Coleman Deans, Chapel Hill, NC (US);
Paul Edward Hinson, Carrboro, NC (US);
Semtech Corporation, Camarillo, CA (US);
Abstract
A system and method is provided for preventing a dropout of an LED current. In one embodiment of the present invention, the system includes a voltage source, a first circuit, a second circuit, a controller, and at least one LED. The first circuit receives a reference voltage from the voltage source, receives set-point current data from the controller, and uses the reference voltage and the set-point current data to produce a threshold voltage. The threshold voltage is then provided to the second circuit, where it is converted into an output current, which is drawn through the LED. The second circuit then compares the threshold voltage to an output voltage corresponding to the output current, and provides an output to the controller. The controller then uses the output to determine whether a dropout has occurred. If a dropout has occurred, then second set-point current data is provided to the first circuit.