Finding Ideal Component SPICE Models

I need simple ideal P- and N-type MOSFET SPICE models for a prototype circuit. Specific models are not important at this stage. KiCAD has ideal models for resistors and capacitors built-in, but, surprisingly, none for MOSFETS. I am searching far and wide for some and I have found nothing.

I do a fair amount of simulation, but I use it as a tool and I am no expert on Spice or modeling. My question is: Is there some reason why you cannot use some existing model out there from ON Semiconductor, Infineon, or other manufacturer? I am not sure what constitutes an “ideal” model. Just to say that the non-ideal aspects of a MOSFET are sort of key to operating it successfully. So a simulation which ignores (whatever you want to ignore) might not work when you build hardware. Certainly, if your circuit does not demand wonderful things from the MOSFET, then a wide variety of MOSFETs ought to work OK.

You’re correct that any MOSFET should work. The problem is finding a SPICE model for any MOSFET. Most of the time, the model I download cannot be interpreted by whatever KiCAD uses for SPICE (I haven’t gotten a straight answer on whether it uses PSPICE, NGSPICE, SPICE3, etc…). I started looking for generic models because that’s what I have done with LTSPICE in the past and I have given up finding working manufacturer models.

Time is becoming a major issue here. If this was LTSPICE, it would take me about 5 actual seconds to place the generic ideal N and P-Type MOSFETS that are built-in. I have been trying to get a MOSFET model to work for a week.

Before anyone asks, no, using other software is not an option. I have as little control over our software as I do over our IT. Please, if a link to is your solution to my problem, just move along. I’d love to use it, but I can’t, end of story.

FWIW, KiCad 7 has built-in models for a bunch of other stuff (including MOSFETs).

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I am trying to think of a good way to poke fun at your typo… :upside_down_face:

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Maybe that’s why is dead to OP? :wink:

You did not tell us what you did, but for sure you did something wrong (because it should take no more than 5 s to attach a model to a symbol).

There is a tutorial available at KiCad Eeschema as GUI for ngspice, tutorial for setting up the simulation, which. gives a step-by-step introduction.

The most simple MOS model is
.model myMOS NMOS
Put this line into a file and attach it to your MOS symbol. Don’t forget to check the node sequence, as ngspice requires drain, gate, source, bulk (source, bulk may be shorted at your symbol to emulate a 3 pin device), but the MOS needs the 4 pins.

If you have only a 3-pin symbol. you will need a little more complex model, a subcircuit model. It may sound like:

.subckt newMOS d g s
M1 d g s s myMOS
.model myMOS NMOS

Put this into a file and attach it to your symbol.