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:
Sep. 11, 2012
Filed:
Jul. 02, 2008
Satoshi Katagiri, Tokyo, JP;
Satoshi Katagiri, Tokyo, JP;
Elpida Memory, Inc., Tokyo, JP;
Abstract
A phase change memory device is constituted of a plurality of memory cells including a plurality of phase change memory elements, which are arranged at intersecting points formed between a plurality of word lines and a plurality of bit lines. A write circuit which operates based on a write voltage source (Vwrite) is controlled by control signals (e.g. WE, RDIS, SDIS, and DIN) output from a control circuit which operates based on a voltage source (VDD), where Vwrite>VDD. All the control signals based on VDD are applied to the gates of N-channel MOS transistors included in the write circuit. This allows adequately high write currents to be supplied to phase change memory elements; and this eliminates the necessity of arranging a potential switch circuit in the write circuit, thus reducing the scale of the phase change memory device.