Basic op amp simulation file

[pascor]

I need a basic .lib simulation file for a “jellybean” op-amp such as an LM358. All I was able to find is an unusable, as-is, .mod file originally from Nat’l Semi via the Github repository at: KiCad-Spice-Library/README.md at master · kicad-spice-library/KiCad-Spice-Library · GitHub I’m sure it must be very detailed and accurate for a wide variety of uses…
Instead, is there a generic op-amp sim model file with basic functionality I can get?

[ML9104]

Always go to the manufacturers first!
You’ll find models for LM324 and LM358 at www.ti.com

[paulvdh]

There are several threads on this forum dedicated to working ngSpice simulations in KiCad. Some examples:

Simulation examples for KiCad8/KiCad9/Eeschema/ngspice

New simulation examples are following here. Up to Class E RF generator I have been using KiCad 8. Now I am switching to KiCad 9. It should be no problem to open KiCad 8 Eeschema files in KiCad 9 for simulation, as the simulator interface did not change. Unfortunately it is not possible the other way round. You may not be able to open KiCad 9 files in KiCad 8 any more. ngspice-44 is typically involved. The previous examples (KiCad 6, ngspice-38) are visible at Simulation examples for KiCad/Ees…

34 Simulation Examples for KiCad 8.0 Using Ngspice

After watching a presentation by Holger Vogt in a Youtube video FOSDEM 2024 - ngspice circuit simulator stand alone and embedded into kicad, I located the source of the examples in a forum post More simulation examples for KiCad/Eeschema/ngspice. To make it easier to play with the examples (and update/maintain them), I have migrated the examples from the forum post (extracted 7z archives and documentation) to this GitHub repository: https://github.com/labtroll/KiCad-Simulations To run any of t…

Those are two of the top links found after a quick search with:
https://forum.kicad.info/search?q=simulation%20examples

[pascor]

(reply has been retracted)

[ML9104]

How did you add the model to your symbol?
The normal way is to open the symbol properties in your schematic, go to simulation model and add the model as file.
But there’s a nasty catch: the window for adding the simulation model has an extra field where you need to select the model name.
This is graphically so badly made that you tend to miss it. Even after years, it still happens to me.

[holger]

@pascor

Instead, is there a generic op-amp sim model file with basic functionality I can get?

Have a look at the KiCad symbol library Simulation_SPICE. The OPAMP symbol has a generic ngspice model attached.

[pascor]

MIL9104: I haven’t found any “bubble gum” `op amp sim models at the TI web site directly usable for NGspice. Where are they? They seem to have only models for their own simulator.

Holger: I successfully substituted this in my test circuit making a comparator from an op amp since I could not find a working comparator sim file.

The zener reference voltage throughout the voltage works as expected as well as the op amp’s comparator function.

I should have run a transient analysis instead of a ramping DC as an input signal. That will be changed shortly.

The red trace is the applied voltage. Why doesn’t the graph scale reach up to 13 volts? Is this a limitation to the model?

[pascor]

(Reply has been retracted)

[ML9104]

@pascor

MIL9104: I haven’t found any “bubble gum” `op amp sim models at the TI web site directly usable for NGspice. Where are they? They seem to have only models for their own simulator.

Just go to the product page, eg, LM358 data sheet, product information and support | TI.com
A bit down you’ll find “Design & development” and there “Design tools & simulation”.
Not too hard, no?

[pascor]

Thanks! To choose any TI part go to: https://www.ti.com/