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. 10, 2007
Filed:
Sep. 10, 2003
Yoshifumi Yaoi, Yamatokooriyama, JP;
Hiroshi Iwata, Nara, JP;
Akihide Shibata, Nara, JP;
Masaru Nawaki, Nara, JP;
Kei Tokui, Chiba, JP;
Yoshifumi Yaoi, Yamatokooriyama, JP;
Hiroshi Iwata, Nara, JP;
Akihide Shibata, Nara, JP;
Masaru Nawaki, Nara, JP;
Kei Tokui, Chiba, JP;
Sharp Kabushiki Kaisha, Osaka-shi, JP;
Abstract
When an input voltage determining circuitdetermines that an input voltage exceeds a prescribed voltage, a control circuitof a positive polarity power selector circuitturns on a first switch SWand turns off second and third switches SWand SW, thereby supplying the input voltage to a memory cell arrayvia the first switch SW. When the input voltage determining circuitdetermines that the input voltage is not higher than the prescribed voltage, the control circuitturns off the first switch SWand turns on the second and third switches SWand SW, thereby supplying a voltage from a charge pumpvia the second and third switches SWand SW. By this operation, the memory element is able to retain storage of two bits or more even if miniaturized, to execute stable operation with a small circuit area and to prevent circuit malfunction attributed to a small current supplied to the memory cell array.