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:
Apr. 14, 1998
Filed:
Aug. 24, 1995
Ikuo Kurachi, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
A semiconductor device of the present invention includes an integrated circuit formed on a first conduction-type semiconductor substrate, an output buffer circuit for outputting a signal obtained from the integrated circuit, a protection circuit for protecting the output buffer circuit and a voltage supply circuit for supplying a voltage to the semiconductor substrate. The output buffer circuit has buffer MOSFETs. The protection circuit has protection elements for preventing electrostatic breakdown of the buffer MOSFETs. Impurity diffusion layers of the buffer MOSFETs are separated from impurity diffusion layers of the protection elements and a field oxide film is disposed therebetween at predetermined intervals. Owing to such a construction, the electrostatic breakdown of each buffer MOSFET can be prevented from occurring.