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. 16, 1993
Filed:
Jul. 18, 1991
Michael P Brassington, Sunnyvale, CA (US);
Reza Moazzami, Oakland, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A circuit and technique for accessing a ferroelectric memory to read polarization states without destruction thereof. A small-amplitude positive polarity pulse is applied to the ferroelectric capacitor, and the resultant positive charge read therefrom. Thereafter, a small-amplitude negative polarity pulse is applied to the ferroelectric capacitor, and the resultant negative charge read therefrom. Because of the nonlinear hysteresis characteristics of the ferroelectric capacitor, the positive and negative readout charges are of different amplitudes. Sense amplifier circuits produce a summation of the positive and negative readout signals, with a resulting summation polarity defining the polarization state initially stored in the ferroelectric capacitor.