SPICE modeling of a JFET from Datasheet

In order to get these parameters we need a datasheet that contains all the graphics required by PSpice Model Editor, and not all datasheets are responding to this feature. In this case we model a dual JFET N-channel transistor 2N5911, and the reference datasheet is the following:

Let’s open PSpice Model Editor, select item “New” from “File” menu, and “New” item from menu “Model”, name the model and select “Junction FET” on “from Model” and “NChannel” on “Channel Polarity”:

Begin to analyze the graphic of gfs transconductance as a function of drain current Id:

Then, fill the first table available on PSpice Model Editor with pairs of values that we can deduce from datasheet graph:

extractbeta

Interpolation of the curve leads us to extract BETA value that’s approximately 0.002141, and RD and RS values that can be taken equal to default value of 1.0 ohms:

Posted in PSpice Modeling from Datasheet and tagged , , .