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:
Dec. 03, 2002
Filed:
Mar. 14, 2001
Applicant:
Inventors:
Akihiko Kanouda, Hitachinaka, JP;
Kenichi Onda, Hitachi, JP;
Norikazu Tokunaga, Hitachi, JP;
Ryouhei Saga, Takasaki, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G05F 1/40 ;
U.S. Cl.
CPC ...
G05F 1/40 ;
Abstract
In a voltage drop chopper type DC-DC converter, in an intermediate load area, a pulse train having a low peak value in the neighborhood of the threshold voltage is applied to a power MOSFET, whereby the power MOSFET is given a high ON resistance and turned on. By doing so, the output voltage is controlled by a PAM (pulse amplitude modulation) switch system for reducing the peak value below the supply voltage.