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. 23, 2004
Filed:
Mar. 22, 2002
Applicant:
Inventor:
Satoshi Tomioka, Nagaoka, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02M 3/335 ; H02M 3/24 ;
U.S. Cl.
CPC ...
H02M 3/335 ; H02M 3/24 ;
Abstract
A switching power supply which feeds energy stored in a choke coil to a load through a freewheeling element when a switching element turns off. The switching power supply includes a freewheeling MOSFET serving as the freewheeling switch element which operates synchronously with the switching element and a surge voltage prevention circuit . The surge voltage prevention circuit detects a timing for a current to flow in the direction that a body diode of the freewheeling MOSFET conducts when an operation stoppage signal to the switching element is outputted, and then turns off the freewheeling MOSFET at the timing.