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:
Feb. 22, 2011
Filed:
May. 14, 2009
Qiang Zong, Shanghai, CN;
Shaohua Fang, Shanghai, CN;
Reixia Fei, Shanghai, CN;
Jia Xie, Shanghai, CN;
Qiang Zong, Shanghai, CN;
Shaohua Fang, Shanghai, CN;
Reixia Fei, Shanghai, CN;
Jia Xie, Shanghai, CN;
Abstract
A startup circuit for a switching-mode power supply (SMPS) includes a first voltage detector configured to trigger the switching-mode power supply from a startup mode to a normal operation mode when an input supply voltage exceeds a first threshold voltage, a current consumption in the first voltage detector in the startup mode being determined by a reverse leakage current of a diode. A feedback circuit is coupled to the first voltage detector and being capable of maintaining a positive feedback loop with a current consumption of no more than a microampere. A second voltage detector is coupled to the first voltage detector and the feedback circuit, and is configured to trigger the switching-mode power supply to switch from the normal operation mode to the startup mode when the input supply voltage is below a second threshold voltage.