Here we introduce how to obtain basic spice models, the types of spice models, folders to save them, and file structure.
In LTspice, the standard registered spice models are mostly Analog Devices’ products. If the model you want to use is not registered as standard, you need to search and obtain it from each component manufacturer’s site as necessary. Incidentally, there are three ways to obtain spice models.
How to obtain the SPICE model
- Download from component manufacturer’s site
- Create by yourself
- Use a spice model creation service (for a fee)
Highly accurate spice models can be purchased from companies that sell them for a fee. We do not introduce them here, but please consider them if necessary.
Two Spice Models
|Device Model||Passive/Active Components|
|Subcircuit model||Equivalent circuit|
Each of these two types has a designated folder for LTspice, with separate files for each category. For example, in the device model category, a spice model is registered by adding a line to the designated file. Registered spice models are listed in Quadcept’s part attributes dialog, so spice models can be easily registered and changed when creating circuit part data or schematics.
It is recommended that spice models be registered when creating component library data in Quadcept, as this will simplify verification work when creating circuits in the future.
Next, we will show you how to obtain a general spice model.
This time, we will show you how to download the spice model of “AD8542” from the website of Analog Devices, Inc. By the way, AD8542 is a subcircuit model.
Search for “model number + SPICE model” on the web and go to the page.
Select “SPICE Models” on the left side of the page and download the model. It is easy to get from Analog Devices site. You can also get spice models from many other manufacturers such as Rohm and Texas Instruments. As mentioned earlier, unavailable and high performance spice models can also be purchased for a “fee”. Please consider this if necessary.
The following are the types of spice models and tips on how to register them.