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. 07, 2000
Filed:
Nov. 17, 1997
Kiyoshi Nishimura, Kyoto, JP;
Rohm Co., Ltd., Kyoto, JP;
Abstract
It is an object of the present invention to provide a ferroelectric memory device including a load capacitor corresponding to an actual read-out time period appropriately and capable of reading out stored data in a high-speed as well as saving electric power consumption. An applying duration 't' (=2.5n seconds) which generates the maximum value of the differential voltage .DELTA.V of approximately 0.87V is selected when a voltage value corresponding the minimum detectable value of the sense amplifier AMP1 is 0.8V. Also, capacitance C of the load capacitor Cb is determined at the capacitance (.apprxeq.1.25 pF) which maximize the differential voltage .DELTA.V when the applying duration 't' is 2.5n seconds. Another applying duration 'tp' (not shown) of read-out voltage Vp is set as 2.5n seconds the same as the applying duration of the voltage Vd for determining characteristics of a capacitor. A duration required for rewrite operation can be shorten when the applying duration 'tp' of read-out voltage Vp is set shorter. In this way, a duration required from read-out operation to rewrite operation can be shorten as well as saving electric power consumption.