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:
Sep. 05, 1978
Filed:
Sep. 07, 1976
Ichiro Ohhinata, Yokohama, JP;
Hitachi, Ltd., , JP;
Abstract
A semiconductor switch circuit comprises a PNPN switch with a gate terminal and having an equivalently four-layered PNPN structure, and a load-current-dividing circuit including at least a transistor. The base and the collector of the transistor included in the load-current-dividing circuit are connected to the cathode and the anode of the PNPN switch, respectively. The load current is divided into two parts of the current. One part of the load current flows into the base of the transistor through the anode and the cathode of the PNPN switch, while the remaining part of the load current flows into the collector of the transistor. Since the greater part of the load current flows into the collector of the transistor, the PNPN switch is not burdened with a large current. Thus, the semiconductor switch circuit permits the gate turn-off operation of the PNPN switch with a self-holding ability, thereby making it possible to cut off a large current.