User Guide

The Bipolar Transistor Test Case 8
-3
The Bipolar Transistor
Test Case
This tutorial fits parameters to a bipolar transistor (BJT) model
using measured data for Ic and Ib versus Vbe at constant Vce.
To load the BJT desi
g
n
1
From the Windows 95 Start menu, select the MicroSim
program folder and then the Schematics shortcut to start
Schematics.
2
From the File menu, select Open.
3
Move to the directory containing
bjtpar.sch
(\MicroSim_root \examples\optimize\bjtpar) and, in the File
Name list, select the schematic file.
Fi
g
ure 8-1
Schematic for the BJT Model Fitting Example
The circuit has voltage sources for Vbe and Vce and an instance,
Q1, of a BJT. Q1 is a QbreakN device with its model reference
set to Qx—the name of a BJT model.
The schematic also includes an instance of a 2N3055. This is the
model that was used to produce the measured data. The 2N3055
in the schematic works as a reference during model fitting.
The QX model definition for this
example is contained in the
bjtpar.inc include file. To check
whether this file is included, from
the Analysis menu, select Library
and Include Files.