What is an IGBT?

What is an IGBT?

IGBT Definition

An Insulated Gate Bipolar Transistor (IGBT) is defined as a semiconductor device that combines the advantages of Power MOSFETs and Power BJTs.

Structure

The IGBT structure includes an additional p+ injection layer, which enhances its performance compared to PMOSFETs.

Switching Characteristics of IGBT

IGBT switching involves distinct turn-on and turn-off times, with specific delay and rise/fall times affecting performance.

Latching Up

Latching up occurs when the IGBT stays on even after the gate voltage is reduced, requiring special commutation circuits to turn it off.

Advantages

• Lower gate drive requirements

• Low switching losses

• Small snubber circuitry requirements

• High input impedance

• Voltage controlled device

• Temperature coefficient of ON state resistance is positive and less than PMOSFET, hence less On-state voltage drop and power loss.

• Enhanced conduction due to bipolar nature

• Better Safe Operating Area

Disadvantages

• Cost

• Latching-up problem

• High turn off time compared to PMOSFET