Phase change memory read circuit having temperature following characteristic

Abstract

The present invention provides a phase change memory read circuit having a temperature following characteristic. The phase change memory read circuit comprises a reference phase change memory array, a phase change memory array, a reference phase change memory cell address registering module, a reference current generation module, a clamping voltage generation module, and a current comparison module. According to the present invention, by sampling the ambient temperatures of different positions of the large-scale phase change memory array and by using the temperature drift coefficient of the phase change unit in the high and low resistance state, the reference current is changed along with the ambient temperature change so as to provide the proper self-tuning characteristic, such that the temperature difference between different physical positions of the phase change memory array is considered, the aliasing of the reference current value and the phase change unit bit line current value is avoided, and the correct read of the readout circuit during the change of the external environment temperature is improved.

Description

technical field [0001] The invention belongs to the technical field of micro-nano electronics, and relates to a phase-change memory reading circuit and method suitable for large-scale phase-change memory with temperature following characteristics, especially for large-scale storage. The temperature difference at the place, and adapt to different external temperature environments, generate a reference current with a certain temperature self-adjustment, so as to improve the reliability of information reading. Background technique [0002] Phase-change memory technology is based on the idea that phase-change thin films can be applied to phase-change storage media proposed by Ovshinsky in the late 1960s and early 1970s. The basic principle of phase change memory is to use electric pulse signal to act on the device unit, so that the phase change material undergoes reversible phase transition between amorphous state and polycrystalline state. By distinguishing the high resistance ...

AI Technical Summary

Problems solved by technology

[0004] Since the resistivity of the phase-change material itself changes with temperature, and the temperature coefficient of the phase-change memory cell in the high-resistance state is significantly greater than that in the low-resistance state, when the external environment temperature changes, the fixed reference current (voltage) adapts to Low stability, it is easy to cause the failure of the read circuit to read data

Images