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:
Aug. 30, 1994
Filed:
May. 21, 1993
Leslie R Avery, Flemington, NJ (US);
David Sarnoff Research Center Inc., Princeton, NJ (US);
Sharp Corporation, Osaka, JP;
Abstract
The invention is a protection circuit for an integrated circuit which includes an SCR switch, a zener diode in parallel with the SCR to trigger the SCR to its on-state, and a zener diode in series with the SCR controls the on-state or clamping voltage of the SCR. The protection circuit is formed in a semiconductor substrate of first conductivity type having a well region of second conductivity type, a first region of first conductivity type in the well and a second region of second conductivity type in the substrate spaced from the well region. The first region, well region, substrate and second region forming the SCR. A third region of second conductivity type is in the well region and contacts the first region to form a first zener diode. A fourth region of second conductivity type is in the substrate and electrically connected to the well region. A fifth region is in the substrate and contacts the fourth region to form a second zener diode.