A Nonlinear Titanium Dioxide Memristor Model for Memory Crossbars Analysis

In this work, a modified and highly nonlinear ionic drift titanium dioxide memristor model and its operation in passive and hybrid memory crossbars are presented. In a combination with a differentiable and continuous step-like function, its application and analysis in LTSPICE are considered. The described memristive model is with an enhanced nonlinearity, it includes activation thresholds and successfully represents the boundary effects for hard-switching mode. The terminal state issues are also resolved by the used modified window function. The obtained results are compared with those, derived by applying the classical Lehtonen-Laiho, Joglekar and Biolek memristor models. The improved window function, used in the suggested model, allows altering the time derivative of the state in a broad range and thus the applied memristor model is able to properly operate at higher-frequency signals, retaining its good switching properties. A comparison between the used models according to several significant criteria is conducted. The correct operation of the proposed model in complex electronic schemes is confirmed.