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:
Nov. 18, 2014
Filed:
Sep. 26, 2011
Jae Hong Jeong, Saratoga, CA (US);
Jae Hong Jeong, Saratoga, CA (US);
Other;
Abstract
A driver circuit for driving light emitting diodes (LEDs). The driver circuit includes a string of LEDs divided into n groups and the n groups of LEDs is electrically connected to each other in series, where a downstream end of group m−1 is electrically connected to the upstream end of group m. The driver circuit also includes a power source coupled to an upstream end of groupand provides an input voltage. The driver circuit further includes current regulating circuits, where each of the current regulating circuits is coupled to the downstream end of the corresponding group at one end and coupled to a ground at the other end. Each of the current regulating circuits includes a sensor amplifier and a cascode having first and second transistors. The driver circuit also includes detectors, where each of the detectors detects a source voltage of the first transistor.