FET Fundamentals Unit 2 – Junction FETS
Shown are the schematic symbols and proper bias voltages of an N-channel and a P-channel
JFET.
NEW TERMS AND WORDS
gate - the FET terminal that corresponds to the base of a transistor.
source - the FET terminal that corresponds to the emitter of a transistor.
drain - the FET terminal that corresponds to the collector of a transistor.
N-channel - an FET device with a P type (doped) gate material.
P-channel - an FET device with an N type (doped) gate material.
channel - the source to drain controlled path for current flow through an FET device.
ohmic region - the linear operating area between a JFET's off and saturated limits.
pinch-off - FET saturation or constant current region; an operating point at which an increase in
drain to source voltage does not produce a change in the drain to source current.
avalanche region - the destructive breakdown area of an FET. It results from excessive drain to
source circuit voltage.
pinch-off - FET saturation or constant current region; an operating point at which an increase in
drain to source voltage does not produce a change in the drain to source current.
EQUIPMENT REQUIRED
F.A.C.E.T. base unit
FET FUNDAMENTALS circuit board
Multimeter
Oscilloscope, dual trace
Generator, sine wave