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. 05, 1983
Filed:
Jul. 18, 1980
Masayoshi Suzuki, Hitachiota, JP;
Akio Sagawa, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In semiconductor switches, erroneous firing is often a serious problem. To overcome this, a semiconductor switch is provided which includes a thyristor of PNPN structure with three PN junctions and with anode, cathode and gate electrodes, a first transistor for short-circuiting at least one PN junction of said thyristor upon its saturation, and a second transistor provided between the anode side or cathode side of the thyristor and the base of said first transistor to cause saturation of the first transistor in accordance with the voltage which is applied to the anode or cathode of the thyristor. The ratio of the time constant of the second transistor to that of said thyristor is not substantially less than 0.5. This ratio is established by using similar plane diffused patterns for the second transistor and a third transistor which is defined by three continuous layers of the thyristor.