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:
Nov. 22, 2005
Filed:
Jan. 16, 2003
Yasushi Nakayama, Tokyo, JP;
Takeshi Ohi, Tokyo, JP;
Ryuichi Hashido, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A drive circuit for a power semiconductor device includes: a sampling signal generating circuit for detecting that an input control signal instructs OFF and outputting a sampling signal at the time instant of start of a Miller period of time of an IGBT; a gate voltage detecting circuit for detecting a Miller voltage of the IGBT at the timing when the sampling signal is inputted and outputting, when the Miller voltage is equal to or larger than a threshold, an over-current detection signal; and a gate voltage controlling circuit for controlling, in response to the over-current detection signal, a gate voltage of the IGBT in such a way that the IGBT is turned OFF at slower speed than in the normal state. Thus, it is possible to suppress a surge voltage which is generated when the IGBT is turned OFF during the flow of an over-current.