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:
Apr. 12, 1994
Filed:
Apr. 24, 1991
Applicant:
Inventors:
Assignee:
Fujitsu Limited, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C / ;
U.S. Cl.
CPC ...
365210 ; 36518907 ;
Abstract
A non-volatile semiconductor memory device comprises an EEPROM cell, a dummy cell, and a sense circuit. The EEPROM cell, the dummy cell and the sense circuit are operatively connected to a drain column line and a control column line, and the sense circuit reads out the content written in the EEPROM cell by the difference between a current flowing through the EEPROM cell from the drain column line and a current flowing through the dummy cell from the control column line. Consequently, write/erase operations of data for each one bit can be carried out in one operation, and access time can be shortened and deterioration of a cell transistor can be decreased in a read-out operation.