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:
May. 29, 2001
Filed:
Dec. 18, 1998
Katsuhiro Kato, Tokyo, JP;
Yasuhiro Fukuda, Tokyo, JP;
Oki Electric Industry Co., Ltd., Tokyo, JP;
Abstract
When a semiconductor integrated device is in an inactive state without being supplied with electric power, depletion type NMOS transistors act as resistors whereby a signal line connected to an input pad is electrically connected to the sources of input transistors via the NMOS transistors. In this situation, if an electrostatic surge is applied to the input pad, the surge is released to a voltage supply line. This ensures that the semiconductor integrated device is prevented from being damaged by the electrostatic surge. When electric power is supplied to the semiconductor integrated device and it becomes active, the NMOS transistors come to behave as insulating elements and thus these NMOS transistors have no adverse effects on the normal operation of the semiconductor integrated device.