Lab at www.docircuits.com - BJT characteristics

1. Access this lab-manual at:
http://www.docircuits.com/lab-manual/9/bjt-characteristics
BJT Characteristics
Aim
Aim is to plot the characteristics of a BJT
Related Experiments
BJT CHARACTERISTICS
Description
This experiment is designed to plot the output characteristics of a generic BJT. The given BJT is connected in the
common emitter configuration. The plot is of the output current against the voltage for the various values of input
current. In other words, it is the plot of IC against VCE for different IB. For a constant IB the current increases as the
voltage increases till it reaches saturation. The characteristics are made up of three regions: cutoff, active and
saturation regions. At saturation, the VCE is almost zero and very high current flows. At cutoff, the output current
will be zero. At the active region, the IC increases linearly with the VCE.
Procedure:
1. Connect the circuit as shown.The values of the DCsources don’t matter as they will be changed throughout the
experiment.
2. Click on Run and select the “DC with Sweep”. We are going to sweep two parameters. DCSource0 from 0 to 2V,
Medium Accuracy. DCSource1 is configured as a current source. (This can be selected on the DC source by clicking
on the “Voltage/Current” button). IB is supplied by DCSource1 and it is varied from 0 to 40 μA. And the VCE is
varied from 0 to 2 V by varying DCSource0.
3. Run the simulation and observe results on the plotter.
Conclusion
As VCE is varied the ammeter reading varies and becomes steady. The plots for each IB value are shown – as varied
from 0 to 40 μA. The operating regions are as shown in the plot.
BJT BASICS