JFET Junction Field Effect Transistor

1
JFET (Junction Field Effect Transistor)

• Unipolar device (one polarity of charge carrier)

• Voltage controlled (gate voltage controls
• drain current)

• High input impedance (?109-1012 ?)

• No minority carrier storage

• Source and drain are interchangeable in most
• low-frequency applications

2
SYMBOLS
p-channel JFET
n-channel JFET
n-channel JFET Offset-gate symbol
3
Operation of a JFET
Drain
-
N
Gate
P
P


DC Voltage Source
-
-
N

Source