Readout amplifying circuit for resistive random access memory (RRAM) cell

Abstract

The invention discloses a readout amplifying circuit for a resistive random access memory (RRAM) cell, and provides a novel readout amplifying circuit for an RRAM cell, which reduces the influence of interference current on reading operation, lowers the overall direct current (DC) power consumption and improves the accuracy of a reference voltage generating circuit. The readout amplifying circuitconsists of a comparative readout level and the reference voltage generating circuit, wherein, the comparative readout level consists of N sense bits, the N sense bits and bit lines of an RRAM cell array are in a relationship of one-to-one correspondence, and each sense bit consists of a sensitive amplifier, a feedback resistor and a voltage comparator; and the reference voltage generating circuit consists of M voltage division elements and an operational amplifier, the voltage division elements in the reference voltage generating circuit are capacitors which are connected in series, and a positive input terminal of the operational amplifier is connected with a voltage division point. By utilizing the readout amplifying circuit, the misread rate can be lowered, the overall DC power consumption can be reduced, and the reference voltage output precision of the reference voltage generating circuit can be improved.

Description

technical field [0001] The invention relates to a readout amplifier circuit on the periphery of a resistive variable memory unit array in the field of integrated circuit design, in particular to a readout amplifier circuit which uses a DC gain change to sample resistance value changes and uses a controllable capacitor voltage divider to generate a reference voltage. Background technique [0002] Non-volatile memory is a kind of memory that can retain the original stored information after power failure, and is widely used in modern electronic systems. There are various types of non-volatile memory, and resistive random access memory (RRAM) is one of them. Due to the characteristics of ultra-high storage density, simple structure, high speed and non-volatility of RRAM, the application prospect is very broad. [0003] The resistive memory cell array is the core of the resistive memory, and is composed of a large number of resistive memory cells according to a certain spatial s...

AI Technical Summary

Problems solved by technology

As the capacity of the resistive memory cell array increases, the number of sneak paths increases, and the interference current will gradually become more serious, resulting in the sense amplifier circuit not being able to correctly identify the resistance state of the resistive memory cell.

[0007] 2. The DC power consumption of the sense amplifier circuit is large

Since the load resistance is used as the element for detecting the resistance state of the resistive memory cell in each readout bit of the comparison readout stage, there is a direct current path from the word line of the resistive memory cell array to the ground, when the resistive memory cell array When the number of bit lines increases, the DC power consumption of the read operation increases accordingly

At the same time, due to the use of resistors in the reference voltage generation circuit as a voltage divider, the input voltage V input There is a DC path to the ground, resulting in a large DC power consumption

The above reasons cause the overall DC power consumption of the sense amplifier circuit to be relatively large.

[0008] 3. The accuracy of the reference voltage generation circuit is affected

The output voltage of the reference voltage generating circuit V ref The precision of the voltage divider has a strong dependence on the matching precision of the voltage divider. In the manufacturing process of integrated circuits, it is not easy to achieve accurate matching of resistors. Since resistors are used as voltage divider components in the reference voltage generation circuit, it is reduced. To ensure the accuracy of the reference voltage generation circuit

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