LTSpice .asc to component conversion

[ronv]

I'm trying to help someone build an EDM machine. I am simulating it in sections since it is getting pretty big. But I would eventually like to simulate the whole thing. It seems like I remember there is a way to "roll up" a schematic into a component. If there is it would be ideal because I could make each section a component. There are not to many inputs and outputs, just more "stuff" that can easily be done on one page of spice. If there is a way I could do it with about 5 sections of components.
Can anyone walk me through it?

 

[MikeMl]

When viewing a schematic, explore the Hierarchy menus.

You can design a "leaf" schematic, put IO ports on it, let LTSpice automatically build a symbol with pins on it. The pin names on the instance match the port names. The symbol will have the same name at the schematic but will have a .asy extention in place of the .asc.

To instantiate the newly-created symbol in a higher-level schematic, click on the NAND gate icon. In the top dialog box, point to the subdirectory where the newly created symbol got put in lieu of ../lib/sym, and then you can place (even multiple) instance(s) of the new symbol.

 

[ericgibbs]

hi Ron,
Its called a hierarchical model, this an example of AD623, IA to shows the method.

E

 

[ronv]

Thanks guys, I'll give it a try.

 

[simonbramble]

just remember if you ground any element inside your "black box" it will connected to node 0 (ground) of the external circuit. This is a gotcha that can bite you if you are not careful.

 

[MikeMl]

just remember if you ground any element inside your "black box" it will connected to node 0 (ground) of the external circuit. This is a gotcha that can bite you if you are not careful.

I always make it a point not to use any ground symbols in subcircuits, and always propagate node 0 in from a higher level using an explicit pin

 

[ronv]

Perfect, since I have a power and logic ground.

Thanks again!