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. 18, 2009
Filed:
Jun. 26, 2006
Tsutomu Ishino, Kyoto, JP;
Tsutomu Ishino, Kyoto, JP;
Rohm Co., Ltd., , JP;
Abstract
A pulse signal generating circuit generates a pulse signal having a duty ratio controlled such that the output voltage approaches a reference voltage. A driver circuit generates first and second gate voltages, which are to be respectively applied to the gates of a switching transistor and a synchronous rectifier transistor, based upon the pulse signal. A threshold voltage generating unit generates a threshold voltage which is synchronous with the second gate voltage, and which is in the high-level state during a period when the synchronous rectifier transistor is to be turned off and in the low-level state during a period when the synchronous rectifier transistor is to be turned on. A light-load detection comparator compares a switching voltage with the threshold voltage, and outputs a light-load detection signal.