Magnetic tunneling junction device model for circuit simulation

In this work, we develop the HSPICE macro model of the magnetic tunneling junction (MTJ) devices for circuit simulation. The macro model exhibits the spin behavior of free layer magnetic moment and automatically changes the magnetic resistance when magnetic moment between free and pinned layer changes. The interlayer coupling effect, metal line resistance and bias-dependent MR ratio are also taken into account. An ingenious approximation is used to model the write magnetic field asteroid curve. This macro model can improve the simulation accuracy of MRAM.