# First time using LTSpice

It's my first time using LTSpice that was required for us to use but our prof didn't know that most of us haven't used ltspice yet. I already have done the schematic diagram but i dont know how to input the parameters, can someone pls help me?

• Right-click on the component. Eventually even Ctrl-Right-click. Yeah, LTspice isn't very intuitive, but once you get used to it, is is very efficient to get things done. – dim Apr 25 '18 at 11:02
• @dim And yet, this is explained in the help, in the introduction. Admittedly, it's one of the more terse help files, but it is explained, and a simple look could save you a ton of headaches later on. – a concerned citizen Apr 25 '18 at 20:07

## 1 Answer

Right-Click on the NMOS4 symbol once placed on the schematic and enter the width and length there. If you have additional parameters, you're better off adding your own .model card, something like this:

.model NMOStest NMOS L=<length> W=<width> Vto=<Vto> ...


where NMOStest is the name you'll be giving to your NMOS. You can see more details about possible parameters in the help (LTspice > Circuit Elements > M). It's quite spartan, but it does help. As for the rest of the calculations, I think that's up to you.

• Thank you! but how do i put the parameters for K' and K'W/L? :/ – Roberto Apr 25 '18 at 12:28
• @Roberto I gave you a direction to read about the MOSFET in LTspice, and about its parameters. If you'll try a bit, you'll spot there, in the table, a certain parameter Kp [A/V<sup>2</sup>], one lambda [1/V], and maybe others, as well (hint: V<sub>t0</sub> is Vto, the one I deliberately mentioned in the control card example). – a concerned citizen Apr 25 '18 at 13:18