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:
Aug. 19, 2014
Filed:
Oct. 04, 2012
Texas Instruments Incorporated, Dallas, TX (US);
Joel Nathan Brassfield, Homer Glen, IL (US);
Ashish Khandelwal, Malden, MA (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A light-emitting diode (LED) driver system includes a control circuit that provides a waveform for driving a power transistor to generate a regulated current through one or more LEDs, and an error amplifier that generates an output compensation signal based on a comparison of a desired regulated current and an actual regulated current through the one or more LEDs. The output compensation signal is used to set an output compensation voltage that sets the duty cycle of the waveform. The LED driver system further comprises a dimming control device configured during a dimming control mode to alternate between dimming-on time periods and dimming-off time periods, and a sample and hold switch having a first state for holding the output compensation voltage fixed during each dimming-off time period, and a second state for restoring the error amplifier to its previous dimming-on operating state upon returning to each subsequent dimming-on time period.