Patent ID: 7672151
Filing Date: 2010-03-02
Classification: G11C

Abstract:
1. A method for reading a non-volatile memory cell, comprising the steps of: activating an access transistor to connect a ferroelectric capacitor serially between a bit line and a drive line, said ferroelectric capacitor having a previously set polarization state; applying a drive pulse via said drive line to said ferroelectric capacitor for transferring a charge therefrom to said bit line, the amplitude of said transferred charge being a function of the polarization state of said ferroelectric capacitor, whereby a charge signal is established on said bit line, and wherein the amplitude of said charge signal is proportional to the charge transferred by the ferroelectric capacitor to the bit line; comparing said charge signal on said bit line with a reference signal and driving said bit line to either a high or low voltage state as determined by a difference between said charge signal and said reference signal; and restoring said previously set polarization state in said ferroelectric capacitor if the polarization state in said ferroelectric capacitor has been changed by said drive pulse, said step of restoring being carried out by a voltage between said bit line and said drive line thereby reestablishing an original polarization state in said memory cell.