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:
Jun. 06, 1995
Filed:
Oct. 26, 1993
Katsushi Asahina, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
Reliability related problems such as destruction of the insulation film and shortened operating life of the MOSFET are prevented in a case where the voltage of an input signal is larger than a power source voltage for a semiconductor integrated circuit device. Where the voltage of an input signal which is received at an input signal terminal (3) is larger than a power source voltage V.sub.DD1, by causing a voltage drop between source-drain of an N channel MOS transistor (Tr4) which has a gate electrode fixed at the power source voltage V.sub.DD1, the voltage of the input signal is shifted. The shifted voltage is then applied to a gate electrode of an N channel MOS transistor (Tr2). That is, the voltage of the input signal is not directly applied to the gate electrode of the N channel MOS transistor (Tr2). Thus, when the voltage of the input signal is larger than the power source voltage for the semiconductor integrated circuit device, by shifting the voltage of the input signal and thereby preventing application of an excessively large voltage to a gate insulation film, enhanced operation reliability is attained.