This article explains how to import a SPICE model with the “.model” statement  into Isis of Proteus. Suppose we want import the PSpice model of an NPN Radio frequency transistor BF199. We have the following SPICE source file:

Run Isis and click on “P” button of “Device” to pickup the generic NPN device:

write “NPN” on the keywords edit field and select “Generic NPN bipolar transistor”

After placing the component on the layout, click on “Text Script Mode” button of left side toolbar and left mouse click on the layout, the Edit Script Block window pops up

Now, copy the text of source SPICE model and paste beetwen the two statements

*SCRIPT SPICE

*ENDSCRIPT

as in the figure below

It’s important to copy the source text between the two statements, otherwise the simulator warns thar can’t recognize the model and replaces it with a default NPN primitive.