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:
Jun. 15, 2010
Filed:
Jan. 24, 2008
Applicants:
Katsumi Ishikawa, Hitachinaka, JP;
Masahiro Nagasu, Hitachinaka, JP;
Dai Tsugawa, Mito, JP;
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K 17/16 (2006.01); H03K 17/30 (2006.01);
U.S. Cl.
CPC ...
Abstract
A subject of the present invention is to reduce noise caused by ringing or the like while reducing turn-on power loss of the element and reverse recovery loss of the diode in a switching circuit of a power semiconductor element to which a SiC diode having small recovery current is connected in parallel. A means for solving the problem is to detect gate voltage and/or collector voltage of the power semiconductor switching element and change gate drive voltage in several stages based on the detected value.