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:
Jul. 27, 2004
Filed:
Jan. 24, 2003
Yasuaki Hirano, Tenri, JP;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
This nonvolatile semiconductor memory device includes a word line regulator circuit , which supplies a voltage to a word line, a program/erase control circuit , which outputs a write control signal to the word line regulator circuit , and a pulse voltage step width storage circuit , which stores information of a voltage increment &Dgr;Vg. The word line regulator circuit supplies a voltage to a word line according to the write control signal from the program/erase control circuit based on the information of a voltage increment &Dgr;Vg stored in the pulse voltage step width storage circuit . A voltage increment &Dgr;Vg by which a threshold voltage change of a memory cell becomes a predetermined voltage can be set for each chip by the pulse voltage step width storage circuit . Consequently, a highly reliable multi-valued write operation can be performed.