Basic Electrical and Electronics Engineering: Unit III: Analog Electronics

Insulated Gate Biplolar Transistor (IGBT)

Construction, Operation, Characteristics, Basic Structure, Symbol, Advantages, Disadvantages

IGBT combines positive attributes of BJT's and MOSFET's.It has 3 terminals gate(G), Emitter (E) and collector(C).

INSULATED GATE BIPLOLAR TRANSISTOR (IGBT)

• IGBT combines positive attributes of BJT's and MOSFET's.

• It has 3 terminals gate(G), Emitter (E) and collector(C).

• 4 layer NPNP.

• Input characteristics same as MOSFET and output is same as BJT.


Operation

• N-channel IGBT turns on when the collector is at positive potential with respect to emitter and also gate is at sufficient positive potential (VGET) with respect to emitter.

• This condition leads to formation of an inversion layer just below the gate, leading to a channel formation and current begins to how form collector to emitter.

• Collector current IC in IGBT constitutes of two components Ie and In [Ie→ due to injected electron and Ih→hole current]

• Ic = Ie + In

In is almost negligible so Ic ≈ Ie


Advantages

• Lower gate drive requirements

• Low switching losses

• Small snubber circuit requirement

• High input impedance

Disadvance

• Cost high

• High turn off time.

Basic Electrical and Electronics Engineering: Unit III: Analog Electronics : Tag: : Construction, Operation, Characteristics, Basic Structure, Symbol, Advantages, Disadvantages - Insulated Gate Biplolar Transistor (IGBT)