RRAM sensitive amplifier

Abstract

The invention discloses an RRAM sensitive amplifier, comprising a storage branch, a reference branch, a comparison and output circuit and a pre-charging enhancement circuit. The storage branch is used for converting state of a variable resistor in a memory cell into corresponding voltage signal Vmat; the reference branch is used for converting reference current into corresponding reference voltage Vref; the comparison and output circuit is used for comparing the voltage signal Vmat with the reference voltage Vref, and outputting standard logic high level or low level corresponding to low or high resistance state of the variable resistor; and the pre-charging enhancement circuit is used for communicating the storage branch and the reference branch during the pre-charging stage. According to the RRAM sensitive amplifier, a function of reading state of the variable resistor in the RRAM memory cell can be successfully realized; with the pre-charging enhancement function, the time of the pre-charging stage is shortened, and consequently, the whole data reading cycle is shortened, data reading speed is increased, and data throughout of the memory is improved. Result of simulation verification shows that data reading cycle is shortened by 10ns-15ns as compared with the data reading cycle in the traditional scheme in the scheme of the invention.

Description

technical field [0001] The invention relates to the field of storage devices, in particular to an RRAM sensitive amplifier. Background technique [0002] Resistive random access memory (RRAM) is a new type of non-volatile information storage technology, which has the characteristics of simple structure, compatible with standard CMOS technology, low operating voltage, low power consumption and high-speed reading and writing. Its storage information unit is made of a metal oxide (such as CuO x , WO x ,HfO x , TiO x , NiO x etc.) realized variable resistors. Under different working conditions, the varistor exhibits bipolar memory characteristics of high resistance state (for example: 100Kohm) and low resistance state (for example: 10Kohm). [0003] Reading the stored information is to convert the state of the variable resistor (high resistance state and low resistance state) into a level signal (low level and high level) that can be recognized by the external circuit. Us...

AI Technical Summary

Problems solved by technology

[0012] Although the above-mentioned existing solutions can successfully realize the reading function of the storage unit, there are still the following disadvantages: 1) The data reading speed is slow, mainly because the pre-charging phase (t0~t1) takes a long time, that is, Vmat stabilizes to the target value The time taken is too long, resulting in the lengthening of the entire data reading cycle, which in turn affects the decline in the data throughput of the memory; 2) There are many devices (including two op amps, a comparator and other circuits), and the layout area is large; especially for multiple The memory of byte (for example 16Bytes) operation will need more sense amplifiers (for example 128), so chip area is larger, and chip cost increases; 3) operating current is big, assuming the operating current of each amplifier and comparator is 50uA, and the operating current of other circuits is 20uA, then the operating current of a sense amplifier is about 170uA, and for a memory operated by multiple bytes (such as 16Bytes), the operating current is at least 128*170uA=21.8mA; at the same time, a large 4) There are many feedback loops (the storage branch and the reference branch each contain a feedback loop), the system instability increases, and the difficulty of design and implementation also increases

Images