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. 14, 1993
Filed:
Nov. 15, 1991
Ciaran J Brennan, Bedford, MA (US);
Charles Stark Draper Laboratory, Inc., Cambridge, MA (US);
Abstract
A ferroelectric space charge capacitor memory system includes a ferroelectric space charge capacitor memory cell having two ferroelectric space charge capacitor memory devices; a write circuit for applying coercive write voltage to each of the memory devices to establish internal polarization fields and space charge regions of opposite polarity in each device, respectively; a bias voltage circuit for applying to each of the devices a bias voltage less than the coercive voltage at a rate slower than the rate of space charge formation to define a capacitive level representative of one of the polarization states; a read signal circuit for introducing to each of the devices a read signal at a rate faster than the rate of space charge formation, which together with the bias voltage is less than the coercive voltage; and a detector responsive to the read signal for indicating the difference in charge transferred by each memory device representing the logical state of the memory cell.