Import Third Party Part Into Ltspice

LTspice is FREE, it’s good too. SPICE netlist is script-like commands for circuit simulations. With LTspice the circuit can be setup graphically with the SPICE netlist living in the background.

LTspice has complete models for Analog Devices, Linear Tech parts, but if you want to simulate a part that is not in the parts list, you can do that too. LTspice has some blank graphical models allowing a simulation model to be attached to it. It’s possible to simulate non-LT or AD parts that have a SPICE .subckt or .model.

Example with a lm358 op-amp

Parts manufactures often supply simulation models for their parts, for a TI LM358 there’s a PSPICE model under Design Tools & Simulations. Or OnSemi has their version under Technical Documentation & Design Resources

LTSpice has a generic opamp opamp2 which has five ports, in+, in-, v+, v-, and out. This should match the same order with the .subckt declaration in the simulation file.

OnSemi LM358 SPICE MODEL.MOD file

* PINOUT ORDER +IN -IN +V -V OUT
* PINOUT ORDER  1   2   3  4  5
.SUBCKT LM358 1 2 3 4 5

TI LMx58_LM2904.CIR file

.subckt LMX58_LM2904 IN+ IN- VCC VEE OUT

Don’t get tripped up by the file extension, as long as its a SPICE or PSPICE simulation model, it should work.

In LTSpice add the generic opamp2

Right click the part, and change the component attribute value

Change the value to the subckt name
Im using the TI’s PSPICE file: LMx58_LM2904.CIR. Open the file in a text editor and find the .subckt name.

.subckt LMX58_LM2904 IN+ IN- VCC VEE OUT

Add spice command .include ‘filename’

And now LTSpice can run the simulation for this lm358