Analysis of Memory Matrices with HfO2 Memristors in a PSpice Environment

The investigation of new memory circuits is very important for the development of future generations' non-volatile and Random Access Memories (RAM) memories and modern schemes for in-memory calculations. The purpose of the present research is to propose a detailed analysis of passive and hybrid memristor-based memory crossbars with separating metal oxide semiconductor (MOS) transistors. The considered memristors are based on HfO2. The transistors are applied to eliminate the parasitic paths in the schemes. For simulations, a previously proposed strongly nonlinear modified window function by the author together with a physical nonlinear memristor model is used. The considered model is adjusted according to the experimental i-v relationship of HfO2 memristors. The i-v relationship obtained by the simulation is successfully fitted to the respective relationship derived by physical measurements. A good coincidence between these characteristics is established. Several basic window functions are also applied for comparison to the corresponding results. The proposed model is analyzed in Personal Simulation Program with Integrated Circuit Emphasis (PSpice) and it is also used for simulation of a 5 x 5 fragment of a memristor memory crossbar with isolating transistors and for the analysis of a 6 x 6 passive memory matrix. The investigated matrices are simulated for writing, reading, and erasing information. It is established that the model proposed could be used for simulations of complex memristor circuits.