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:
Jul. 07, 1992
Filed:
Apr. 14, 1988
Applicant:
Inventors:
Yu C Kao, Pittsburgh, PA (US);
Donald L Miller, Export, PA (US);
Scott G Leslie, Pittsburgh, PA (US);
Assignee:
Powerex, Inc., Youngwood, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ;
U.S. Cl.
CPC ...
357 43 ; 357 34 ; 357 13 ; 357 52 ;
Abstract
A power bipolar transistor has a MOSFET located within the base region, the MOSFET shorting the transistor emitter and base regions together when the bipolar transistor is in an off condition with a large base to collector voltage. The bipolar transistor is provided with floating guard rings, and the gate of the MOSFET is connected to one of these floating guard rings, so that when the depletion region from the base to collector junction reaches this floating guard ring, the MOSFET gate receives a voltage to turn on the MOSFET and provide the emitter to base short.