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. 25, 2011
Filed:
Feb. 10, 2009
Shinji Takeda, Yokohama, JP;
Yoshiharu Hirata, Yokohama, JP;
Shinji Takeda, Yokohama, JP;
Yoshiharu Hirata, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor memory device comprises: a write circuit including a latch circuit configured by two inverters having a positive side power supply terminal supplied with a first voltage and a negative side power supply terminal supplied with a second voltage; and a write state machine controlling the first and second voltages. When writing data to a memory cell, the first voltage is changed to a second value that is lower than a first value. When writing data to a memory cell, the second voltage is changed to a third value that is lower than the second value. The write state machine lowers the second voltage to an intermediate value between the second value and the third value and, while maintaining this intermediate value, lowers the first voltage from the first value to the second value.