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:
Oct. 26, 2010
Filed:
Nov. 09, 2007
Morihito Hasegawa, Kasugai, JP;
Takashi Matsumoto, Kasugai, JP;
Ryuta Nagai, Kasugai, JP;
Fujitsu Semiconductor Limited, Yokohama, JP;
Abstract
A DC-DC converter reducing reverse current and maintaining high conversion efficiency under a light load. The DC-DC converter perform pulse width modulation (PWM) or pulse frequency modulation (PFM) and includes a drive control circuit generating a first drive signal and a second drive signal activating and inactivating a first transistor and a second transistor in a complementary manner. A reversed flow detection circuit detects current flowing to the second transistor and generates a detection signal controlling activation and inactivation of the second transistor. A detection signal invalidation circuit, coupled to the reversed flow detection circuit and the drive control circuit, receiving an operation switch signal and invalidating the detection signal in response to the operation switch signal during at least a certain period of the PWM.