Insulated Gate Bipolar Transistor (IGBT)

Insulated Gate Bipolar Transistor (IGBT)

• The power BJT has advantage of low on state power dissipation, but it cannot be switched at faster rates due to longer turn-off time.
• The power MOSFET can be switched at much higher frequency but has a drawback of higher on state power loss.
  
  
  
• Therefore attempts we made to combine BJTS and MOSFETS monolithically on the same silicon wafer to develop a new device that will have the best qualities of both, BJT and MOSFET.
• The new device is known as Insulated Gate Bipolar Transistor (IGBT).
• Other names to this device are GEMFET, COMFET (conductivity modulated field effect transistor), IGT (insulated gate transistor) and bipolar mode MOSFET or bipolar MOS transistor.

Features of IGBT

The important features of IGBT are as follows

1. Low on state voltage drop.
2. Low on state power loss.
3. It has a higher switching frequency than that of a power BJT.
4. IGBT has the best qualities of BJT and MOSFET.