What Is an IGBT?
An IGBT (Insulated-Gate Bipolar Transistor) is a power transistor that combines the easy voltage drive of a MOSFET with the high power-handling of a BJT.
How Does It Work?
Its input is driven like a MOSFET by gate voltage (low drive power), while its output behaves like a BJT and carries high current/voltage with low loss. It combines the best of both.
Comparison With MOSFET and BJT
| Property | MOSFET | IGBT |
|---|---|---|
| Voltage range | Low-medium | High (600 V+) |
| Switching speed | Very fast | Medium |
| High power | Good | Very good |
High Voltage and Current
Because an IGBT can carry hundreds of volts and tens/hundreds of amperes, it's indispensable in heavy power applications. However, at very high frequency it's not as efficient as a MOSFET.
Where Is It Used?
Inverters, motor drives, welding machines, solar power converters and electric vehicle (EV) power stages.
Tail Current
As an IGBT goes to cutoff, the BJT part inside it keeps conducting current for a moment; this is called tail current. It creates switching loss and explains why an IGBT isn't as efficient as a MOSFET at very high frequency.
Common Mistakes
- Using it at high frequency: switching losses rise; at very high frequency a MOSFET is a better fit.
- Underestimating gate drive: at high power a proper gate driver and protection are essential.
- Skipping cooling: high power means serious heat.
Frequently Asked Questions
IGBT or MOSFET?+
Why are IGBTs used in EVs?+
Search parts related to "What Is an IGBT?"
Find the right part by comparing price, stock and distributors.