Scott Frederick Leslie

US Patent:

51287420, Jul 7, 1992

Filed:

Apr 14, 1988

Appl. No.:

7/181632

Inventors:

Yu C. Kao - Pittsburgh PA
Donald L. Miller - Export PA
Scott G. Leslie - Pittsburgh PA

Assignee:

Powerex, Inc. - Youngwood PA

International Classification:

H01L 2972
H01L 29784

US Classification:

357 43

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.

US Patent:

45729476, Feb 25, 1986

Filed:

May 29, 1984

Appl. No.:

6/615019

Inventors:

Yu C. Kao - Pittsburgh PA
Scott G. Leslie - Penn Hills PA

Assignee:

Westinghouse Electric Corp. - Pittsburgh PA

International Classification:

H01L 1114
H01J 3912

US Classification:

250211J

Abstract:

The present invention provides a method for triggering a light triggered thyristor (LT. sup. 2) which method comprises using a light source to provide background excitation of carriers in at least the amplifying gate areas of the LT. sup. 2 prior to triggering the device. The background excitation is of a low level and will not trigger the device or cause excessive leakage current. At the desired time a second light signal is used to trigger the LT. sup. 2.