Spice Models

There are two types of models in Spice, the ‘intrinsic’ model and ‘.subckt’ models.

Intrinsic Models

Intrinsic models are built into Spice, and have defined characteristics (specified by model equations, i.e. R = V/I). These devices require parameters that ‘tune’ the device equations for a specific output characteristics. Using a product called “MODPEX”, we can generate a set of model parameters using the following process:

Specify Source Data

The process of developing a model starts with receiving a device datasheet from the manufacturer(click on pictures at left for larger image)

View Datasheet

Generate Data for use as Model Input

The graphs on the datasheet are scanned, and device performance values are digitized from the scanned datasheets.

View Scanned Datasheet

Regression and Optimize Model Parameters

MODPEX extracts the model parameters through the use of an optimizer engine, which varies the model parameters to minimize the error of the model performance to the digitized data sheet performance values.

View MODPEX Optimization

Test and Document Model Performance

When the parameters are fully extracted, MODPEX tests the device and generates a datasheet of the model performance vs. the original datasheet values.

View Model Performance Data

Standard turn-around time for a device model generated with MODPEX is 2-4 days from the receipt of the device datasheet and purchase order/credit card info/wire transfer.

Custom Subcircuit models

Interface Technologies also generates custom subcircuit models such as OpAmps and Switchmode controllers, Optocouplers, etc. These devices are more involved from an engineering perspective, and quoted by device. Please contact us with your requirements.
Pricing varies slightly depending on the type of model required.

for an exact quotation. We’ll generally need a datasheet for the device that you need quoted. If you have one and send it with the request, that is very useful.