Electronic Devices and Circuits – EET2222

 

Lab 8 – JFET Characteristics

 

 

Reading:

·        Floyd, Thomas L., Electronic Devices, 7th Ed., Sections 7-1 and 7-2.

 

 

Objectives:

After completing this experiment, you will be able to:

·        Measure and graph the drain and transfer characteristics for a JFET.

·        Measure VGS(off) and IDSS for a JFET.

 

 

Procedure:

 

1.      Use the circuit in Figure 1 to take data and plot the drain characteristic plot (VDS vs ID) and transfer characteristic (plot VGS vs ID) for the 2N5486 JFET.    Measure ID for values of VDS of 0V, 0.5V, 1V, 2V, 3V, 4V, 5V, 10V, and 20V and for values of VGS from 0 to -5 volts in steps of 1 V.  Plot ID on the vertical axis for both graphs, and label each axis with suitable units and calibration points.  See Figure 7-13 on page 338 of the text for an example of this graph.

 

2.      Determine VGS(off) and IDSS from the characteristic curves of the JFET.

 

The report for this lab is due at the end of the lab period.  Please use the green engineering paper.

 

 

Questions:

1.   Explain how to find IDSS from the characteristic curves of a JFET.

 

 

Figure 1:

 

 

 

 

Figure 2: