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:
Jan. 09, 1990
Filed:
Dec. 23, 1987
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L / ; H01L / ; H01L / ;
U.S. Cl.
CPC ...
357 2313 ; 357 13 ; 357 234 ; 357 238 ; 357 35 ; 357 41 ; 357 43 ; 357 51 ;
Abstract
A protective circuit consisting of a resistor and MOSFET in a diode form and a switching element are connected to a bonding pad in order to prevent destruction of an internal circuit consisting of one or more MOSFETs. The switching element may consist of a parasitic MOSFET whose source and drain regions are formed by well regions. One of the well regions is connected to a semiconductor region as a guard ring.