Difference between IGBT and MOSFET

DifferencesIGBTMOSFET

Insulated Gate Bipolar Transistor (IGBT) and Metal Oxide Semiconductor Field Effect Transistor (MOSFET) are two types of transistors that are the basic building blocks of modern electronic circuits. Both IGBT and MOSFET are voltage-controlled devices. However, they are different in various aspects. Go through this article to get a basic overview of how these two transistors operate and how they are different from each other.

What is IGBT?

IGBT stands for Insulated Gate Bipolar Transistor. IGBT is a three terminal semiconductor device which is used in various electronic circuits for switching and amplification of signals. The three terminals of the IGBT are: emitter (E), collector (C) and gate (G).

The control signal is applied to the gate terminal of the IGBT. The IGBT has the combined features of BJT (Bipolar Junction Transistor) and MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

The insulated gate bipolar transistors (IGBTs) are classified into following two types −

  • Punch through IGBT (also called asymmetrical IGBT)
  • Non Punch through IGBT (also called symmetrical IGBT)

What is MOSFET?

MOSFET stands for Metal Oxide Semiconductor Field Effect Transistor. A MOSFET is a four terminal semiconductor switching device which is used for switching and amplifying the signals in the electronic circuits.

The four terminals of the MOSFET are: source (S), drain (D), gate (G) and body (or substrate). Sometimes, the body terminal of the MOSFET is connected to the source terminal, which makes it a three-terminal device

Based upon the construction and principle of operation, the MOSFETs are of following four types −

  • N-Channel Enhancement MOSFET
  • P-Channel Enhancement MOSFET
  • N-Channel Depletion MOSFET
  • P-Channel Depletion MOSFET

Difference between IGBT and MOSFET

The following table compares and contrasts the various features of IGBT and MOSFET −

ParameterIGBTMOSFET
Full FormIGBT stands for Insulated Gate Bipolar Transistor.MOSFET stands for Metal Oxide Semiconductor Field Effect Transistor
DefinitionIGBT is a three terminal semiconductor switching device used in the electronic circuits for switching and amplification of signals.MOSFET is a four terminal semiconductor switching device which is also used as switching and amplification.
TerminalsIGBT has three terminals, which are: emitter (E), gate (G) and collector (C).MOSFET has four terminals which are: source (S), gate (G), drain (D) and body (or substrate). Sometimes, the body terminal is merged with the source, making it a three terminal device.
PN junctionIGBT has PN junctions in its construction.MOSFET does not have any PN junction in its construction.
SuitabilityIGBT is suitable for medium to high current conduction and controlling.MOSFET is suitable for low to medium current conduction and controlling.
Voltage and power handling capacityIGBT has ability to handle very high voltage and high power.MOSFET is capable of handling only low to medium voltage and power.
Operating frequencyIGBT can only be used for relatively low frequencies, up to a few kHz.MOSFET can be used for very high frequency (of the order of MHz) applications.
Forward voltage dropWhen IGBT is conducting current, it produces comparatively low forward voltage drop.MOSFET produces higher forward voltage drop than IGBT.
Turn OFF timeFor IGBT, the turn-off time is larger than MOSFET.The turn-off time of a MOSFET is smaller than IGBT.
Switching speedThe switching speed of IGBT is relatively low.The switching speed of MOSFET is very high.
Transient voltage & current handling abilityIGBT has ability to handle any transient voltage and current.MOSFET cannot handle transient voltage and current. Thus, the operation of a MOSFET gets disturbed when the transient occurs.
Saturation voltageFor IGBT, the saturation voltage is low.MOSFET has high saturation voltage.
CostIGBT is costlier than MOSFET.The cost of a MOSFET is relatively low.
ApplicationsIGBTs are extensively used in high power AC applications such as in inverter circuits.MOSFETs are used in low power DC applications like in power supplies.

Conclusion

Both IGBT and MOSFET are types of transistors. These two types of transistors are widely used in modern electronic and power electronic circuits. In this article, we highlighted the major differences between IGBT and MOSFET and how they operate.

raja
Updated on 01-Jun-2022 14:02:49

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