Hi

I have a strange question. I downloaded a MOSFET LTspice model (.asy) from official website and saved it in the directive. However, It still shows "unknown subcircuit." If I use ideal NMOS4, the simulation works. Could someone help me with why it happens and how to deal with it?
I attached my simulation file and MOSFET .asy file.

Thank you

 

The problem is that your symbol does not reference a sub-circuit file. This sub-circuit specification might be in a library, or it might be in a standalone file. It is definitely missing from my system and yours.

You do not want to use the generic NMOS part in LTspice; it produces very squirrely results, and you DO NOT want to use the NMOS4 symbol - that is for chip designers and I'm pretty sure you have no clue how to use it.

I went to the onsemi site and it knows nothing about a spice model for the part. what official website did you actually go to??

 

The problem is that your symbol does not reference a sub-circuit file. This sub-circuit specification might be in a library, or it might be in a standalone file. It is definitely missing from my system and yours.

You do not want to use the generic NMOS part in LTspice; it produces very squirrely results, and you DO NOT want to use the NMOS4 symbol - that is for chip designers and I'm pretty sure you have no clue how to use it.

I went to the onsemi site and it knows nothing about a spice model for the part. what official website did you actually go to??

Hi

I downloaded MOSFET file from
https://www.onsemi.com/products/discrete-power-modules/mosfets/ntmts001n06cl#technical-documentation

This MOSFET spice model is .asy file, so I downloaded it and saved it in my directive. But I don't know why it is not working. In my previous experience, I can download the .lib file as MOSFET spice model, then I use .lib MOSFET .lib, it will work. But in this case, the MOSFET model is .asy file. How to make the symbol does reference a sub-circuit file ?

Thank you

 

In my previous experience, I can download the .lib file as MOSFET spice model

But the file you now have is an .asy file, not a .lib file. You need both files.

 

The ".asy" files are NOT models, they are graphical symbol outlines with pin definitions. T6_60V_LL_rev4p6_ltspice.txt is the name of the text file included in the .zip file. It is an encrypted subcircuit file with a plain text header. You can change the file extension from ".txt" to ".lib" and use an include statement on your schematic.

 

I downloaded the actual library file from the website, renamed it with a .lib extension, cleaned up your schematic a bit and ran the following simulation:



All three files work fine when they are in the same folder. Good luck going forward.

 

I downloaded the actual library file from the website, renamed it with a .lib extension, cleaned up your schematic a bit and ran the following simulation:

View attachment 288141
View attachment 288142
All three files work fine when they are in the same folder. Good luck going forward.

Hi

I follow your suggestions, and it works! I am very much appreciated it.
Thank you so much.

Jiaqi

 

Hi

I follow your suggestions, and it works! I am very much appreciated it.
Thank you so much.

Jiaqi

Happy to help