Electrical – Model of Mosfet Switching in LTspice

This is defined as a subcircuit:

.SUBCKT PSMN2R0_30PL DRAIN GATE SOURCE

LTSpice needs this to have somewhat special treatment, so you will need to do the following:

CTRL+Right click on the device and you will get this window:

Now edit the Prefix and Value lines: The prefix for a subckt is 'X'. The model name is precisely as defined in the lib file.

Now click OK. You will need to add a spice directive on your schematic:

.include PSMN2R0_30PL.lib This assumes it is in the same directory as the simulation circuit.

LTSpice should now be happy with the part.

Here is what you should see on the schematic:

You can, of course, add it to the LTSpice model tree, but I find it easier to use this method.

You can do that by using a "Arbitrary Behavioral Voltage or Current Sources" where you can define the arbitrarily define the behavior of you current source. I will not go in to the details of Arbitrary Behavioral Voltage or Current Sources since this is found in the Help of LTSpice

Additionally from http://ltwiki.org/index.php5?title=Undocumented_LTspice You can find the following section:

Resistors Behavioral Resistors Create a behavioral resistor by right-mouse-button clicking on its Value field and edit its value to read: R=. This feature is undocumented, but is considered permissible to use. The expression syntax is the same as for a general behavioral source (see B-sources in Help). The resistance must not go to zero and negative values can lead to convergence problems, so it is advisable to restrict its values to within a meaningful range as per the following Value example: R = limit(1,100k,V(1,2)*I(V1)) ; R stays between 1 ohm and 100k To plot an I-V curve, start by using the differential cursor to plot the voltage across the resistor. First click and hold down the left-mouse-button (red probe icon) on one side of the resistor and then drag and drop the black probe icon on the other side. Finish by dragging the mouse pointer over the x-axis (a ruler icon will appear) and the click the left mouse button to bring up the Horizontal Axis menu. Change the Quantity Plotted from "time" to "I(R1)" (assuming R1 is your behavioral resistor).