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:
Jan. 30, 2001
Filed:
Oct. 12, 1999
Applicant:
Inventor:
Kenji Hibino, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C 7/02 ;
U.S. Cl.
CPC ...
G11C 7/02 ;
Abstract
It is an object of the present invention to prolong the life, and increase the reliability, of a reference voltage generation circuit which generates word line voltages for use in a mask ROM which uses the multiple-valued technology. The circuit, which uses series-connected P-channel MOS transistors P,P,. . . Pm and parallel-connected dummy cell transistors C,C,. . . C,n to generate a reference voltage T,V at the node point, has dummy cell transistors C,C,. . . C,n, with a threshold value lower than that of the dummy cell transistors C,C,. . . C,n, between the output end of the reference voltage T,V and the dummy cell transistors C,C,. . . C,n.