Part I
For the equivalent of data as would be obtained from chip measurements, data are generated using the EKV simulator with the goal of obtaining Level 3 simulator model parameters. An example follows, based on the LabVIEW simulator. These plots could also be obtained, for example, from LTspice.
The plot is saved as a Cluster Global Variable, as shown.
Data vi
Here is a curve-fitting simulation computer with an example input from the data. This is for UO, and since parameter vb depends on UO, it must be updated with UO as shown.
NMOS Parameter Extractor
The three iteration files are in series in a loop. The Loop halts when the change of UO is small as set as 100 u. 
UO
Iteration – Variable vx is a generalization and is UO in this example. Loop runs until deltaUO (per loop) is less than 1 u.
Iteration function. Function f sum value is the mean difference between points, relative.
Global Variables UO and vb (Level 3 parameter) are contained in ICON UO vb. Level 3 simulator in the Loop uses these variables from Global Variables. Loop runs for all index values. Two plots are compared lower, right (above plots).
Sum – Slope
UO uses f sum, and halts for an assigned minimum value. The sum is the mean of the relative difference of points, thus relative to one. The indicator in the plot is the difference in drain currents, mean. The fact that this is not a constant value versus vg is an indication of a difference between Level 3 and EKV.
The slope function is a LabVIEW straight-line curve fit to the difference of the two plots, ekv and Level 3 in this example.
VTO Function – Slope Fit
KAPPA – Slope Fit
Index for the beginning of the saturation region is computed as shown here.
Complete OC simulation. NMOS.
PMOS
Parameters
VMAX, TOX, NSUB and THETA are assigned. ETA = 0 gives the best fit.
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