Operating conditions analysis of memristor model

Electronics, 2018

The investigation of new memory schemes is significant for future generations of electronic devices. The purpose of this research is to present a detailed analysis of the processes in the memory elements of a memory section with memristors and isolating Metal Oxide Semiconductor (MOS) transistors. For the present analysis, a modified window function previously proposed by the author in another memristor model is used. The applied model is based on physical nonlinear current-voltage and state-voltage characteristics. It is suitable for illustration of the processes in the memristors for both writing and reading procedures. The memory scheme is simulated using a nonlinear drift model with an improved window function. The used model was previously adjusted according to the reference Pickett model. The memory circuit is analyzed for writing and reading information procedures. The memristor current-voltage relationship is compared to physical experimental characteristics and to results a...

One significant area of nanotechnology is nanoelectronics and a recent development in nanoelectronics is the discovery of the memristor, a fundamental circuit element. A memristor is essentially a nonvolatile nanoscale programmable resistor whose resistance, or memristance to be precise, is changed by applying a voltage across or current through, the device. Memristor has the potential to replace transistors in the digital circuit of upcoming days. Research is in full swing to find the compatibility of this device with existing CMOS technology. Throughout this paper such possible application of the memristor is investigated through SPICE simulation. The initial goal of the paper was to simulate the device characteristics. The secondary goal was to make circuits with the device. Standardization of device model is a big problem in memristor research, which is why a comparison of various models is also presented in this work. The paper has ended with a summary of our work done and possible scopes for future work.

— While hardware in a computer have developed greatly, users still has faced problems with its speed, and memory in terms of its performance. The recent developments in memristors made it possible to reduce the problems, as memristive models have been be designed to suit the requirements of time. However, different characteristics are expected from memristors depending upon its applications. The paper aims to compare three major models of memristors focusing on their advantages and limitations. It identifies the most suitable model of memristor that satisfies the memristive device conditions. Out of the three models, Voltage threshold adaptive memristor model (VTEAM) fits into the requirements and it has sufficient accuracy and computational efficiency. Keywords— Memristors, VTEAM, Threshold Adaptive Memristor Model, Boundary Condition Model

—The realization of the missing fourth element by Hewlett-Packard in 2008, the memristor, adds new promising technology that enables the continuing improvement of performance, power and cost of integrated circuits and keeping Moore's law alive. Memristor-based technology provides much better scalability, higher utilization when used as memory, and overall lower power consumption. This paper presents a detailed study of existing memristor modeling using Matlab simulations. We studied three different models to predict the behavior of the memristor device. We developed the Matlab algorithms for all models and analyzed them for their compatibility with the experimentally established characteristics of HP memristor, as well as their viability for use in memory circuits. We discussed all the difficulties with these models and adopt a modified model that gives more realistic description of a memristor device.

IEEE Journal on Emerging and Selected Topics in Circuits and Systems

Memristors show great potential for being integrated into CMOS technology and provide new approaches for designing computing-in-memory (CIM) systems, brain-inspired applications, trimming circuits and other topologies for the beyond-CMOS era. A crucial characteristic of the memristor is multi-state 1 switching. Memristors are capable of representing information in an ultra-compact fashion, by storing multiple bits per device. However, certain challenges remain in multistate memristive circuits and systems design such as device stability and peripheral circuit complexity. In this paper, we review the state of the art of multi-state memristor technologies and their associated CMOS/Memristor circuit design, and discuss the challenges regarding device imperfection factors, modelling, peripheral circuit design and layout. We present measurement results of our in-house fabricated multi-state memristor as an example to further illustrate the feasibility of applying multistate memristors in CMOS design, and demonstrate their related future applications such as multi-state memristive memories in machine learning, memristive neuromorphic applications, trimming and tuning circuits, etc. In the end, we summarize past and present efforts done in this field and envisage the direction of multi-state memristor related research.

The fourth fundamental circuit element-Memristor, was mathematically predicted by Prof. Leon Chua in his seminal research paper in IEEE Transaction on Circuit Theory on the symmetric background. After four decade in 2008, researchers at the Hewlett-Packard (HP) laboratories reported the development of a new basic circuit element that completes the missing link between charge and flux linkage, which was postulated by Chua. The new roadmap in the field of circuit designing, soft computing, memory technology and neuromorphic applications are emerged out very quickly in scientific community due to memristor. However the commercial device level memristor is not realized and reported in the literature until now. This paper overviews the some of the pioneer and state of art development in the view of memristor. The criticism constrains about memristor in scientific fraternity are also discussed.

2016

For past 180 years, circuit theory is studied with three fundamental circuit elements, the resistor, the capacitor and the inductor. The memristor (short for memory resistor) is a yet quite unknown circuit element. It was predicted from the theory arguments nearly 40 years ago, but not realized as a physical component until recently. Memristors are labelled as a significant candidates for building a better storage, higher capacity and more efficient performance. The device, memristor has great potential to replace conventional flash memories in near future. In this paper a brief survey on memristor models is done and a PSpice model of the equivalent circuit of the titanium-dioxide memristor is presented based on the current-voltage relationship. This paper will discuss the fundamental properties, basic device model and prominent applications of memristor as an advancement in fundamental circuit element.

As conventional memory technologies are challenged by their technological physical limits, emerging technologies driven by novel materials are becoming an attractive option for future memory architectures. Among these technologies, Resistive Memories (ReRAM) created new possibilities because of their nanofeatures and unique I–V characteristics. One particular problem that limits the maximum array size is interference from neighboring cells due to sneak-path currents. A possible device level solution to address this issue is to implement a memory array us-ing complementary resistive switches (CRS). Although the storage mechanism for a CRS is fundamentally different from what has been reported for memristors (low and high resistances), a CRS is simply formed by two series bipolar memristors with opposing polarities. In this paper, our intention is to introduce modeling principles that have been previously verified through measurements and extend the simulation principles based on memristors to CRSdevices and, hence, provide an analytical approach to the design of a CRS array. The presented approach creates the necessary design methodology platform that will assist designers in implementation of CRS devices in future systems.

Proceedings of the IEEE, 2000

This paper presents SPICE ready circuit models that system designers can use to accurately measure the behavior of memristor-based large systems. ABSTRACT | The nonvolatile memory property of a memristor enables the realization of new methods for a variety of computational engines ranging from innovative memristive-based neuromorphic circuitry through to advanced memory applications. The nanometer-scale feature of the device creates a new opportunity for realization of innovative circuits that in some cases are not possible or have inefficient realization in the present and established design domain. The nature of the boundary, the complexity of the ionic transport and tunneling mechanism, and the nanoscale feature of the memristor intro-duces challenges in modeling, characterization, and simulation of future circuits and systems. Here, a deeper insight is gained in understanding the device operation, leading to the development of practical models that can be implemented in current computer-aided design (CAD) tools.

2012

The memristor was proposed over 40 years ago by Leon Chua as the missing 4 th twoterminal nonlinear circuit element. Recently HP announced the first fabrication of the device following memristor circuit rules. HP's device is a crossbar resistive hysteretic switch designed for nonvolatile high density memory applications. In this thesis wellknown one-dimensional drift models, which assume sinusoidal voltage sources, were used to predict level of frequency sensitivity in hysteresis curves and instantaneous power curves for memristors. Drift model simulation tests, with ac voltage sources, indicate that the memristor frequency response scales inversely with an identified time constant predicted from physical properties and memristor dimensions. Simulations tests also demonstrate a procedure to obtain maximum in the memristor's hysteresis loop opening. The previously established nonlinear and linear drift models for ac sources were reanalyzed in this thesis to predict current voltage hysteresis with digital type square wave sources. Simulation results were compared with current voltage hysteresis data reported for HP's memristor.