A method of sensing a resistance change memory device includes preparing a memory cell including a variable resistance element storing different data on the basis of a variable resistance, and a switching element connected to the variable resistance element and performing a threshold switching operation, measuring a first cell current by applying a first read voltage to the memory cell, the first read voltage being selected in a threshold-sensing range of a current-voltage characteristic curve of the memory cell, measuring a second cell current by applying a second read voltage to the memory cell, the second read voltage being selected in a resistance-sensing range of the current-voltage characteristic curve, and when at least one of the first cell current and the second cell current is greater than a corresponding reference current, outputting a data signal having a first logic value as data stored in the memory cell.

A data sensing apparatus adapted for sensing read-out data of a memory apparatus includes a sensing reference voltage generator, a sensing reference current generator, and a sense amplifier. The sensing reference voltage generator receives a reference voltage, generates a reference current according to the reference voltage and a control signal, and generates a sensing reference voltage according to the reference current. The sensing reference current generator receives the sensing reference voltage, and generates a sensing reference current according to the sensing reference voltage and the control signal. The sense amplifier receives the sensing reference current and a read-out current from the selected memory cell, and senses a current difference between the sensing reference current and the read-out current to generate the read-out data.

A memory device includes a sense amplifier coupled to a first read voltage during a first phase of a read operation and a second read voltage during a second phase of the read operation. A first and second bias voltages are based on the first and second read voltages and corresponding current on a bit line. A first capacitor includes a terminal coupled to the first and second bias voltages. A first amplifier includes an input coupled to another terminal of the first capacitor and another input coupled to a common mode voltage during the first phase and to a reference voltage during the second phase. A second capacitor includes a terminal coupled to an output of the first amplifier. A second amplifier includes an inverting input coupled to another terminal of the second capacitor and another input coupled to a common mode voltage.

Techniques are provided for managing voltages on memory cells in a cross-point array during a read operation. The techniques apply to vertical layer thyristor memory cells and non-thyristor memory cells. Voltages on selected bitlines (e.g., corresponding to memory cells from which data is to be read), are set to a read voltage level. Voltages on unselected bitlines (e.g., corresponding to memory cells from which data is not to be read and which are not to be disturbed) are set to a de-bias voltage level that is different from the read voltage level.

Devices and methods for determining resistive states of resistive change elements in resistive change element arrays are disclosed. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements by sensing current flow. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements without the need for in situ selection devices or other current controlling devices. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can reduce the impact of sneak current when determining resistive states of resistive change elements.

Devices and methods for determining resistive states of resistive change elements in resistive change element arrays are disclosed. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements by sensing current flow. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can determine resistive states of resistive change elements without the need for in situ selection devices or other current controlling devices. According to some aspects of the present disclosure the devices and methods for determining resistive states of resistive change elements can reduce the impact of sneak current when determining resistive states of resistive change elements.

A nonvolatile memory device comprises: resistive memory cells each of which takes either a variable state or an initial state, the resistive memory cells including at least one resistive memory cell in the initial state; and a read circuit that comprising a resistance detection circuit that obtains resistance value information of the at least one resistive memory cell, and a data generation circuit that generates digital data corresponding to the resistance value information. The resistance detection circuit applies a second read voltage to the at least one resistive memory cell to obtain the resistance value information. The second read voltage is larger than a first read voltage and smaller than a voltage of a forming pulse that is an electrical stress for changing from the initial state to the variable state. The first read voltage is for reading a resistive memory cell in the variable state.

A memory using mixed valence conductive oxides is disclosed. The memory includes a mixed valence conductive oxide that is less conductive in its oxygen deficient state and a mixed electronic ionic conductor that is an electrolyte to oxygen and promotes an electric field effective to cause oxygen ionic motion.

Disclosed herein is a memory cell including a memory element and a selector device. Data may be stored in both the memory element and selector device. The memory cell may be programmed by applying write pulses having different polarities and magnitudes. Different polarities of the write pulses may program different logic states into the selector device. Different magnitudes of the write pulses may program different logic states into the memory element. The memory cell may be read by read pulses all having the same polarity. The logic state of the memory cell may be detected by observing different threshold voltages when the read pulses are applied. The different threshold voltages may be responsive to the different polarities and magnitudes of the write pulses.

According to one embodiment, a memory device includes a memory cell including a resistance change memory portion and a switching portion, and a voltage applying circuit carrying out, at a time of writing data to the memory cell, an operation of applying a voltage of a first polarity to the memory cell and applying a first voltage to the memory cell, an operation of applying a voltage of a second polarity to the memory cell and applying a second voltage to the memory cell, an operation of applying a voltage of the first polarity to the memory cell and applying a third voltage to the memory cell, or an operation of applying a voltage of the second polarity to the memory cell and applying a fourth voltage to the memory cell.