A phase change memory readout circuit and method

Abstract

The invention discloses a phase-change memory readout circuit and method, comprising a fully differential readout circuit and a pre-charging circuit. The fully differential readout circuit uses a differential comparison circuit to compare the current on the phase-change memory and the resistance value of the phase-change memory The reference current in the critical state of high and low resistance is compared and judged to read the logic value of the storage unit; the pre-charging circuit pre-charges the parasitic capacitance on the bit line connected to the phase-change memory before reading the phase-change memory. The phase change memory reading method provided by the present invention precharges the parasitic capacitance on the bit line of the phase change memory before reading the phase change memory, which reduces the delay caused by charging the parasitic capacitance in the reading process. , the reading speed is fast, and it is suitable for reading large-scale phase change memories. In addition, the present invention uses a fully differential readout circuit to read the phase change memory, offsets the non-ideal factors in the circuit by making a difference, improves the matching of the circuit, and thus improves the accuracy of the readout circuit.

Description

technical field [0001] The invention belongs to the technical field of peripheral circuits of a phase-change memory, and more particularly relates to a readout circuit and method of a phase-change memory. Background technique [0002] Phase change memory is a non-volatile phase change memory based on a certain chalcogenide thin film. The phase change material can achieve rapid and reversible changes in the amorphous state and crystalline state to achieve the function of storing data. The material is amorphous When the material is in a high-resistance state, it represents data "0", and when the material is in a crystalline state, it represents a low-resistance state, representing data "1". [0003] When reading the data stored in the phase change memory, it is necessary to apply the read voltage V to the bit line at one end of the memory cell. read When the storage material is in a crystalline state and an amorphous state, its resistance value is different, so the current fl...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the defects of the prior art, the purpose of the present invention is to propose a phase change memory readout circuit and method, aiming to solve the readout problem caused by the time delay when charging the parasitic capacitance in the readout process in the prior art. slow speed problem

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