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. 02, 2005
Filed:
Feb. 20, 2003
Hideaki Tanishima, Kasugai, JP;
Hideaki Tanishima, Kasugai, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An input/output buffer that protects a circuit from voltage signals provided from an external device. The input/output buffer includes a reference power generation circuit connected to a high voltage power supply and a low voltage power supply to convert the voltage of an external voltage signal and generate reference power. The reference power generation circuit has a protection circuit including a plurality of MOS transistors for decreasing the voltage of the external voltage signal to a predetermined voltage when the input/output buffer is not supplied with the voltage of the high voltage power supply. Each of the MOS transistors has a back gate connected to a predetermined node at which the voltage is less than the voltage of the high voltage power supply and greater than the voltage of the low voltage power supply.