Bipolar junction transistors (BJTs) are current-controlled, operate with both majority and minority charge carriers, and consist of three terminals: emitter, base, and collector. Field effect transistors (FETs) are voltage-controlled, use only majority charge carriers, and have terminals: source, drain, and gate. FETs typically have higher input impedance and are often preferred for their low heat generation in applications, while BJTs are favored for low current applications and certain amplification roles.

2.  Bipolar junction transistors are bipolar devices, in
this transistor there is a flow of both majority &
minority charge carriers.
 Field effect transistors are unipolar devices, in this
transistor there are only the majority charge carriers
flows.
 Bipolar junction transistors are current controlled.
 Field effect transistors are voltage controlled.

3.  In many applications FETs are used than bipolar
junction transistors.
 Bipolar junction transistor consist of three
terminals namely emitter, base and collector. These
terminals are denoted by E, B and C.
 Field effect transistor consist of three terminals
namely source, drain and gate. These terminals are
denoted by S, D and G.

4.  The input impedance of field effect transistors has
high compared with bipolar junction transistors.
 A BJT needs a small amount of current to switch on
the transistor . The heat dissipated on bipolar
stops the total number of transistors that can be
fabricated on the chip.
 Whenever the ‘G’ terminal of the FET transistor has
been charged, no more current is required to keep
the transistor ON.

5.  The BJT is responsible for overheating due to a
negative temperature co-efficient.
 FET has a +Ve temperature coefficient for stopping
over heating
 BJTs are applicable for low current applications.

6.  FETS are applicable for low voltage applications.
 FETs have low to medium gain
 BJTs have a higher max frequency and a higher cut
off frequency.

9.  Bipolar Transistor >> Field Effect Transistor
 Emitter – (E) >> Source – (S)
 Base – (B) >> Gate – (G)
 Collector – (C) >> Drain – (D)

12.  The BJT is used as an amplifier.
 The BJT is used as an oscillator.
 It is used for wave shaping in chipping circuits.
 It is used as a modulator.
 It is used as a detector or demodulator.
.

13.  LOW NOISE AMPLIFIER.
 BUFFER AMPLIFIER.
 CHOPPERS
 MULTIPLEXER
 MOSFETS

14. THANKXS