Memristive State Equation for Bipolar Resistive Switching Devices Based on a Dynamic Balance Model and its Equivalent Circuit Representation

Abstract

A memory state equation consistent with several experimental observations is presented and discussed within the framework of Chua's memristive systems theory. The proposed equation describes the evolution of the memory state corresponding to a bipolar resistive switching device subjected to a variety of electrical stimulus.

Fundamentals and SPICE Implementation of the Dynamic Memdiode Model for Bipolar Resistive Switching Devices

“…As the second criterion for assessing the model behavior, the DMM switching dynamics is discussed next. It is worth emphasizing that the switching properties of the memory equation (8) for constant and ramped voltage signals were reported in [34]. (8) complies with the expected characteristic switching times (SET and RESET) for a constant bias condition (Fig.…”

“…Deviations from these exponential laws in the low voltage region have also been reported but are disregarded in this work [39]. If for any reason, the SB and SF effects do not need to be considered, taking VS()=VS a constant reference SET voltage and  =1 in (10) and (11), respectively, the switching dynamics becomes exclusively voltage-controlled as originally assumed in [34]. This behavior is typical of ECM cells in which abrupt RESET transitions are observed.…”

“…As reported in [34], a very convenient differential equation for the memory state variable  that complies with a number of experimental observations in memristive structures is:…”