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:
Jun. 04, 1991
Filed:
Sep. 06, 1989
Masaaki Terasawa, Akishima, JP;
Hidefumi Mukohda, Akishima, JP;
Yoshikazu Nagai, Akishima, JP;
Yasunori Ikeda, Kawagoe, JP;
Kazunori Furusawa, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi VLSI Engineering Corp., Tokyo, JP;
Abstract
A writing high voltage of one polarity or an erasing high voltage of another polarity is selectively fed, in accordance with a writing or erasing operation mode, via a switch MOSFET to the word line of a non-volatile memory element designated by an address signal. The potential of a well region, where the switch MOSFET is existent, is changed in conformity with the switching action of the relevant switch MOSFET so as to control the switch MOSFET. Due to this arrangement, the potential of the well region with the non-volatile memory elements existing thereon can be retained at a fixed value, so that the high voltage generator is required merely to drive the selected word line of the memory array (and not the well in which the memory elements are formed). Consequently, the requisite current supply capability of the high voltage generator can be diminished.