FET Fundamentals Unit 4 – JFET Current Source
Exercise 1 – JFET Current Source Operation
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to measure the output current of a JFET
constant current source using different resistive loads. You will verify your results with a
multimeter.
DISCUSSION
- A constant current source supplies a fixed value of current to a varying load (RL).
- A JFET becomes a constant current source when its gate and source terminals are shorted
and it is placed in series with the voltage source and load resistor. - The JFET must be operating in the pinch-off (P), or saturation, region for it to function as a
constant current source. VDS >VP^
NOTES