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. 22, 2000
Filed:
Nov. 17, 1997
Takayuki Suzu, Tokyo, JP;
Kenji Hibino, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A voltage generation circuit for a multivalued cell type mask ROM includes partial circuits of the same number as the row number of memory cell transistors. Each of the partial circuits includes a cell part circuit, which includes a memory cell transistor and a resistor, which is formed to have the same resistance as the resistance parasitically added to a source and a drain of a memory cell transistor. Each of the partial circuits is supplied with the same signal as the signal supplied to a corresponding word line, so that the partial circuit corresponding to the word line of a selected memory cell transistor is selected to generate a voltage interlocked with a variation in the threshold caused by a difference between the source potential and the substrate potential.