Nonvolatile memory device using resistance material and method of driving the nonvolatile memory device

摘要

Provided is a nonvolatile memory device using a resistance material and a method of driving the nonvolatile memory device. The nonvolatile memory device comprises a resistive memory cell which stores multiple bits; a sensing node; a clamping unit coupled between the resistive memory cell and the sensing node and provides a clamping bias to the resistive memory cell; a compensation unit which provides a compensation current to the sensing node; a sense amplifier coupled to the sensing node and senses a change in a level of the sensing node; and an encoder which codes an output value of the sense amplifier in response to a first clock signal. The clamping bias varies over time. The compensation current is constant during a read period.

主权项

1. A nonvolatile memory device comprising:
a resistive memory cell which stores multiple bits; a sensing node, wherein a cell current flows from the sensing node through the resistive memory cell; a clamping unit coupled between the resistive memory cell and the sensing node, the clamping unit providing a clamping bias to the resistive memory cell, wherein the clamping bias varies over time; a compensation unit which provides a compensation current to the sensing node, wherein the compensation current is constant during a read period; a sense amplifier coupled to the sensing node, the sense amplifier sensing a change in a level of the sensing node at a period of time when the cell current is equal to the compensation current; and an encoder which codes an output value of the sense amplifier in response to a first clock signal.