What Is an IGBT?

An IGBT (Insulated Gate Bipolar Transistor) is a transistor whose input section has a MOS structure and its output section has a bipolar structure. This transistor has the characteristics of a MOSFET with high input impedance and high switching speed, and the characteristics of a bipolar transistor with low saturation voltage.
See IGBT Structure for the structure of the IGBT.

Features of IGBTs

The features of IGBTs when compared with power MOSFETs and bipolar transistors are shown below.

Item	Power MOSFET	Bipolar Transistor	IGBT
Structure (arrows indicate the direction of the drain current / collector current)	N-channel	NPN
Circuit Diagram
Control Systems	Voltage control	Current control	Voltage control
Driving Power	Small	Large	Small
Switching Speed	Fast	Slow	Medium
Breakdown Voltage	About 30 V to 800 V	About 50 V to 800 V	About 400 V to 1200 V
Increasing the Current	Easy (about 1 A to 100 A)	Difficult (about 2 A to 25 A)	Easy (about 15 A to 40 A)
Applications	Low Stepping Motor Low-voltage/high-voltage brushless DC motor Switching power suply	Audio Low-voltage/high-voltage brushless DC motor Solenoid	High-voltage brushless DC motor Inverter

IGBT Structure

This section describes the structure and features of IGBTs. Compared to the punch-through type, the non-punch-through type and field-stop type have faster switching speed, lower loss, and thinner / smaller size.

Structure	Punch-through (PT) Type	Non-punch-through (NPT) Type	Field-stop (FS) Type
Section View
Switching Speed	Slow	Fast	Fast
Short Circuit Withstand Time	Short	Long	Medium
Manufacturing Difficulty	Easy	Difficult	Difficult