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. 26, 2013
Filed:
Mar. 27, 2011
Tsung-wei Huang, Taipei, TW;
Shui-mu Lin, Taichung, TW;
Nang-ching Yeung, Zhubei, TW;
Ti-ti Liu, Taipei, TW;
Huan-chien Yang, New Taipei, TW;
Tsung-Wei Huang, Taipei, TW;
Shui-Mu Lin, Taichung, TW;
Nang-Ching Yeung, Zhubei, TW;
Ti-Ti Liu, Taipei, TW;
Huan-Chien Yang, New Taipei, TW;
Richtek Technology Corporation, Hsin-Chu, TW;
Abstract
The present invention provides a transistor switch on a light emitting device channel, the transistor switch receiving a control voltage VG. A current source circuit controls the current on the light emitting device channel, the current source circuit requiring a minimum voltage VR for normal operation. The present invention further provides a dynamic headroom controller circuit which compares a voltage VS at a current outflow end of the transistor switch with the voltage VR to determine the relationship between the voltage VS and the voltage VR when the control voltage VG is higher than a reference voltage VH, and adjusts the voltage difference between the voltage VS and the voltage VR accordingly.