Method and circuit for reading data from a ferroelectric memory cell

摘要

Data stored in a ferroelectric capacitor in a ferroelectric memory cell are read by applying a preliminary voltage to the ferroelectric capacitor to increase its polarization if a certain data value is stored, then applying a series of read voltages to produce a potential responsive to the stored data. The preliminary voltage may be applied either before or after one terminal of the ferroelectric capacitor is placed in a floating state, which is maintained while the series of read voltages is applied. Application of the preliminary voltage provides an increased reading margin if the ferroelectric capacitor has partially lost polarization while storing the certain data value, by restoring some of the lost polarization.