SPICE Simulation Models

The National Instruments SPICE Simulation Fundamentals series is your free resource on the internet for learning about circuit simulation. The series is a set of tutorials and information on SPICE simulation, OrCAD pSPICE compatibility, SPICE modeling, and other concepts in circuit simulation.

For more information, see the SPICE Simulation Fundamentals main page.

The series is divided among a number of in-depth detailed articles that will give you HOWTO information on the important concepts and details of SPICE simulation.

Circuit simulation is an important part of any design process. By simulating your circuits, you can detect errors early in the process, and avoid costly and time consuming prototype reworking. You can also easily swap components to evaluate designs with varying bills of materials (BOMs).

An important key to performing accurate and successful SPICE simulation is to use high quality SPICE models. While most circuit simulation packages such as Multisim come with thousands of components and SPICE simulation models, frequently designers need to use a part that does not exist in the available database. When these situations arise, the software tool will typically have a way of adding custom components and models to the database. Multisim for example has a detailed component creation wizard that will guide designers through the process of defining custom parts for simulation and PCB layout (See Creating Custom Components in Multisim).

A SPICE model is a text-description of a circuit component used by the SPICE Simulator to mathematically predict the behavior of that part under varying conditions. SPICE models range from the simplest one line descriptions of a passive component such as a resistor, to extremely complex sub-circuits that can be hundreds of lines long.

SPICE models should not be confused with pSPICE models. pSPICE is a proprietary circuit simulator provided by OrCAD. While some pSPICE models are compatible with SPICE, there is no guarantee. SPICE is the most widely used circuit simulator, and is an open standard.

Some SPICE simulation programs such as Multisim include model makers to automatically generate SPICE models for various components. Multisim version 10.1 has 24 SPICE Model makers.

The best place to look for SPICE models is to browse the vendor or manufacturer’s website. Listed below are some of the most popular chip vendors that supply SPICE models on their website.