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:
Dec. 16, 2008
Filed:
Mar. 23, 2007
Akira Umezawa, Shinagawa-ku, JP;
Jin Kashiwagi, Yokohama, JP;
Akira Umezawa, Shinagawa-ku, JP;
Jin Kashiwagi, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A non-volatile semiconductor memory device comprises a redundant memory cell to store address data of a defect cell in a memory cell array. A first decoder circuit is given a first drive voltage to provide a control signal to the redundant memory cell. A dummy memory cell has a threshold voltage corresponding to the redundant memory cell. A second decoder circuit is given a second drive voltage corresponding to the first drive voltage to provide a control signal to the dummy memory cell. A comparator circuit compares data to be read out of the dummy memory cell with data actually read out of the dummy memory cell.