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. 15, 2005
Filed:
Sep. 19, 2002
Kanji Natori, Fujimi-machi, JP;
Kanji Natori, Fujimi-machi, JP;
Seiko Epson Corporation, Tokyo, JP;
Abstract
The invention provides a non-volatile semiconductor that prevents an output from a charge pump from lowering below an operation voltage even in a read operation, and reduces the capacity of a pool capacitor to thereby reduce the size of the apparatus. The invention can include a strong charge pump that generates 5.0V and a power supply voltage of 8.0V. The power supply voltage is supplied to constant voltage circuits. The constant voltage circuits generate voltages corresponding to the respective read, program and erase operation modes. The operation voltage required at the time of programming is 8.0V. In contrast, the operation voltage required at the time of reading is 3.0V. In other words, the charge pump outputs a voltage sufficiently higher than the operation voltage at the time of reading. With this, the output of the charge pump has a margin, such that, an output greater than the operation voltage can always be secured even when the output lowers through setting of the operation voltages. Accordingly, the capacity of the charge capacitor that pools the output of the charge pump can be reduced, and thus the apparatus can be reduced in size.