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:
Mar. 16, 2004
Filed:
Dec. 20, 2002
Kanji Natori, Fujimi-machi, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
In a non-volatile semiconductor memory device of the present invention, a level sense circuit controls operation of an oscillation circuit to make an output voltage of a charge pump circuit equal to a setting voltage. The level sense circuit detects a change of the output voltage of the charge pump circuit to a second setting voltage, which corresponds to a second operation mode and is set by a control circuit, after a switchover from a first operation mode to the second operation mode controlled by the control circuit. This results in detection of an end timing of operation of a discharge circuit, which is driven at the time of the switchover from the first operation mode to the second operation mode. The control circuit stops the operation of the discharge circuit, based on a result of detection of the end timing. This arrangement of the present invention effectively shortens a time period required for enabling an access at the time of the switchover of the operation mode without significantly increasing the total space of the non-volatile semiconductor memory device.