Difference between BJT and Power MOSFET

In this article we will learn about the basic difference between BJT and Power MOSFET . We will also understand that how many type of layer in BJT and MOSFET. We will know that Power MOSFET as a switich working. We will study about the BJT (Biopolar Junction Transistor) .

Difference between BJT and Power MOSFET
BJT(Bipolar Junction Transistor)

BJT and MOSFET as a Switch Workng.

Now we are going to know that how BJT and Power MOSFET work as a switch.

The switching characteristic of power MOSFET is influenced largely by the internal capacitance of the device and the internal impedance of gate drive circuit.

In electronic circuits where switching speed should be high the BJT is used as switching element.

Difference between BJT and Power MOSFET

         BJT(Bipolar Junction Transistor)

         Power MOSFET

 This is Bipolar junction transistor having three terminals.  Base, Emitter and Collector.

 This is basic metal oxide semiconductor field effect transistor. Which having  four terminal

(a)    Gate (b) Drain (c) Source (d) Substrate.

.It may be in two types

(a)    NPN type (b) PNP type

 This may the classified into four types (a) n-channel enhancement type (b) p-channel enhancement type (c) n-channel, deflection type (d) p-channel,defelection types

 This is used as a switch and constructed of germanium or Silicon semiconductor.

 The MOSFET is used as the two terminal resistor and constructed of layer of metal oxide and semiconductor  these are difference between bjt and power mosfet.

 This operates in three regions. (a) Saturation (b) Active (c) Cut-off

 The MOSFET operate in two regions. (a) Enhancement Type (b) Depletion Type

 Input Impedance of BJT is low.


 Power MOSFET has high input impedance (mega ohm). It is also difference between BJT and Power MOSFET.

 BJT has higher switching losses but lower conduction loss.

 Power MOSFET has lower switching losses but it’s on –resistance and conduction losses are more.

 BJT at lower operating frequencies.

 Power MOSFET at higher operating frequencies.

 BJT is current controlled device.

 Power MOSFET is voltage control device.

 BJT has negative temperature coefficient.

 Power MOSFET has positive temperature coefficient.

 BJT, secondary breakdown does occur.

 Power MOSFET, secondary breakdown does not occur.

 BJT is in lower voltage ratings.

 Power MOSFET is in higher voltage ratings.

Difference between BJT and Power MOSFET

Hence, these are some differences between BJT and Power MOSFET. If you will find any incorrect in above article you comment below in comment box.


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