A Stable SPICE Macro-Model for Magnetic Tunnel Junctions for Applications in Memory and Logic Circuits

A generalized circuit macro-model has been developed representing field-switchable magnetic tunnel junctions (MTJs) characterized by two distinct voltage-dependent resistance values in parallel and antiparallel states. General-purpose subcircuit implementations are designed for a switchable voltage-dependent resistor capable of implementing using any version of SPICE, and thus the users are not restricted to HSPICE. Convergence related problems previously reported have been addressed. Transient simulation of a flash-comparator circuit using three MTJs in series is successfully demonstrated showing the robustness of the model.