Abstract: A ferroelectric memory device with plate line segments free from the capacitive plate line segment coupling in a read/write operation, and a method of accessing the memory device. The memory device includes a floating protection circuit for protecting unselected plate line segments from being floated during a read/write operations. The floating protection circuit prevents data disturbance due to the capacitive plate line segment coupling. In a data write method of the memory device, a sense amplifier corresponding to a bit line is activated after a voltage corresponding to a data bit to the bit line is applied. In a data read method of the memory device, the sense amplifier is activated and then a column gate corresponding to the bit line is selected.

Abstract: Integrated circuit memory devices contain a ferroelectric random access memory cell array and a ferroelectric reference cell array electrically coupled to a plurality of bit lines, a sense amplifier and a plate/bit line selection switch, coupled to the plurality of bit lines, for configuring selected bit lines as plate lines by selectively coupling first ones of the plurality of bit lines to the sense amplifier and by selectively coupling second ones of the plurality of bit lines to a plate line, in response to a column select signal. The inclusion of a selection switch and related driving circuits eliminates the need to provide extra dedicated plate lines because each of the bit lines can be at least temporarily configured as a plate line during reading and writing operations.

Abstract: A nonvolatile ferroelectric semiconductor random access memory device and a method for protecting ferroelectric memory cell capacitors from data damage are provided. The contents of the FRAM cells are protected against damage when a power supply voltage goes lower than a predetermined threshold voltage level. Since chip power off time is about several milliseconds and it takes several nanoseconds for a memory chip to perform a normal operation such as a read/write operation, the memory device completes the current read/write operation during either unexpected power down or power off mode, thereby protecting data stored in ferroelectric memory cells against damage when a power supply voltage goes down.

Abstract: Ferroelectric memory devices contain an array of ferroelectric memory cells therein and control circuits for enabling the performance of nondestructive read operations. The memory cells of a device contain a ferroelectric memory cell and each memory cell contains a ferroelectric capacitor having a first electrode electrically coupled to a plate line and an access transistor electrically coupled in series between a bit line and a second electrode of the ferroelectric capacitor. A decoder circuit is also provided. The decoder circuit is electrically coupled to the access transistor of the memory cell by a word line and performs the function of, among other things, turning on the access transistor during a read time interval.

Abstract: A semiconductor memory device having a unit memory cell consisting of, a ferroelectric capacitor having a first and second electrodes, and an access transistor connected to the first electrode of the capacitor and to the bit line, is disclosed. An imprint compensation circuit for applying a predetermined voltage to the first electrode through the write path of the memory device, or for applying a signal in the form of pulse to the second electrode, where data access of the memory device is prohibited, in order to imprint the ferroelectric capacitor in first and second directions from the reference point, creating a normal polarization characteristic.

Abstract: The speed gap between rise and fall times of a buffer biased by a power supply having a power supply voltage, the speed gap varying in a first manner with respect to the power supply voltage and in a second manner inverse to the first manner with respect to a bias current supplied to the buffer, is controlled by generating the bias current such that the bias current varies inversely with respect to the power supply voltage, thereby compensating for fluctuations in the power supply voltage and maintaining the speed gap within a predetermined range when the power supply voltage is greater than a power supply voltage threshold level.