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:
Nov. 24, 2009
Filed:
Sep. 25, 2006
Yasue Yamamoto, Osaka, JP;
Yasuhiro Agata, Osaka, JP;
Masanori Shirahama, Shiga, JP;
Toshiaki Kawasaki, Osaka, JP;
Yasue Yamamoto, Osaka, JP;
Yasuhiro Agata, Osaka, JP;
Masanori Shirahama, Shiga, JP;
Toshiaki Kawasaki, Osaka, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A nonvolatile semiconductor memory device for storing data by accumulating charge in a floating gate includes a plurality of MOS transistors sharing the floating gate. In the device, a PMOS is used for coupling during writing and an n-type depletion MOS (DMOS) is used for coupling during erasure. Coupling of channel inversion capacitance by the PMOS is used for writing and coupling of depletion capacitance by the n-type DMOS is used for erasure, thereby increasing the erase speed without increase of area, as compared to a conventional three-transistor nonvolatile memory element.