How To

How to define a model parameter so that it is visible on schematic and easily editable from schematic itself?

Answer

You can define a model parameter on schematic using PARAM part. This gives user flexibility to display and edit a specific model parameter on schematic.

Example : Requirement to display and edit model parameter Vto of JFET model on schematic

Follow below mentioned steps :

1. Place the part ‘PARAM’ on the schematic from special.olb library from location <cadence installation folder>\tools\capture\library\pspice

2. Add a new property Vto on PARAM by selecting it and doing right mouse click > Edit Property. Display its name and value on the schematic.

This allows you to edit this property value on the schematic by double clicking on the property.

Next modify the model definition so that model parameter Vto value is read from above PARAM part property Vto. For this;

3. Edit the part model by selecting the JFET part > right mouse click > Edit PSpice model
This opens the model in model editor.

4. Change the value of Vto to {Vto}

5. Save the model and close model editor. This creates a new local model for this design. The original model file (.lib) is not modified.

6. Now run the simulation and see that value of Vto is read from the schematic (as defined on PARAM part). You can change this value before simulation run as required.