Getting started


Step1.  Download MTJ spice model.
Step2.  Extract .zip file.
Step3.  Open MTJ_write.sp file (MTJ write example)
Step4.  Set MTJ dimensions and material parameters: Ms0, P0, alpha, RA and initial temparature
                (Ms0: saturation magnetization, P0: polarization, both at zero Kelvin temperature.) 
Step5.  Select anisotropy type using parameter 'MA':
	          ex) In-plane magnetic anisotropy: MA='0' 
                         Perpendicular magnetic anisotropy: MA='1' 
Step6.  Select the initial state of free layer using parameter 'ini', and apply voltage with correct polarity. 
	       Magnetization of the fixed layer will be set automatically according to the 'ini' value. 
	           ex) Antiparallel to parallel switching : ini='1' with positive voltage 
	                  Parallel to antiparallel switching: ini='0' with negative voltage
Step7.  Run SPICE simulation

Downloads


Model files Parameters (default values)
Free layer dimensions Material Ms0 P0 Alpha RA
In-plane MTJ 32nm x 96nm x 2.44nm CoFeB 1210 0.69 0.0062 5
Crystalline perpendicular MTJ 45nm x 45nm x 0.45nm FePt 1210 0.62 0.03 5
Interface perpendicular MTJ 65nm x 65nm x 1.48nm CoFeB 1210 0.69 0.006 5
By using our MTJ compact model, you agree to acknowledge the "UMN MTJ SPICE model, online: http://mtj.umn.edu" in your publications or presentations.

Simulation examples


1. Input parameters for in-plane MTJ (antiparallel to parallel switching)
    
2. Input parameters for crystal perpendicular MTJ (antiparallel to parallel switching)
    
3. Input parameters for interface perpendicular MTJ (antiparallel to parallel switching)
    
4. STT-MRAM read and write waveforms using MTJ SPICE model