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. 30, 1999
Filed:
Jul. 23, 1997
Tetsuya Katayama, Aichi-ken, JP;
Takeshi Miki, Okazaki, JP;
Junji Hayakawa, Okazaki, JP;
Hiroyuki Ban, Aichi-ken, JP;
Denso Corporation, Kariya, JP;
Abstract
An analog switching circuit comprises an insulated-gate field-effect transistor (Q20) having two n-type input-side and outpu-side semiconductor regions (201, 202) and a p-type semiconductor substrate region 203, for controlling conductiveness between an input terminal (IN) and an output terminal (OUT) based on a gate potential. A surge pulse detecting circuit (1020), responsive to an electric potential (Vi) of the input terminal (IN), produces a detection signal of a surge pulse equivalent to a forward bias of a PN junction formed between the semiconductor substrate region (203) and the input-side semiconductor region (201). A substrate potential setting circuit (1010) varies an electric potential of the semiconductor substrate region (203) in response to the electric potential (Vi) of the input terminal (IN) when aby detection signal is produced. Furthermore, a gate potential control circuit (1030) varies the gate potential of the insulated-gate field-effect transistor (Q20) in the same direction as the electric potential of the semiconductor substrate region (203) when the detection signal is produced.