MOSFET vs IGBT: Which Power Switch Should You Choose?

1. What is the difference

Both power MOSFETs and IGBTs are used to switch high currents, but they are built differently. A MOSFET is a majority-carrier device — current flows through a resistive channel — while an IGBT is a minority-carrier device with a bipolar output stage that behaves like a transistor in series with a diode.

That one difference drives almost every trade-off: MOSFETs switch fast but conduct with a resistance that grows with temperature; IGBTs have a roughly fixed saturation voltage but turn off more slowly and carry more switching loss.

2. Conduction losses

A MOSFET conducts like a resistor, so its loss is P = I² × R_DS(on). R_DS(on) roughly doubles from 25°C to 150°C, so hot MOSFETs conduct worse.

An IGBT has a saturation voltage V_CE(sat) of about 1.8–2.2 V that stays fairly flat across temperature. At low-to-moderate current the MOSFET wins; at high current (roughly above the crossover point set by V_CE(sat) vs I²R) the IGBT becomes more efficient.

Parameter	MOSFET	IGBT
Loss model	I² × RDS(on) (rises with temp)	VCE(sat) × I (roughly flat)
Typical VCE(sat) / RDS(on)	RDS(on) 5 mΩ–200 mΩ	VCE(sat) 1.8–2.2 V
Best at	low current, fast switching	high current, high voltage

3. Switching losses

MOSFETs switch in tens of nanoseconds and are comfortable above 100 kHz. IGBTs switch slower and their turn-off tail adds loss that becomes significant above roughly 20 kHz, which is why IGBT converters usually run in the 2–20 kHz band.

For a rule of thumb: below ~60 kHz and above a few hundred volts, an IGBT is often the economical choice; for 100 kHz+ or low-voltage power, a MOSFET is usually better.

4. Voltage and current ratings

Silicon MOSFETs are practical from 20 V to about 650 V (SiC MOSFETs go higher). IGBTs typically start at 600 V and reach 1200–1700 V+, covering industrial drives, solar inverters and UPS.

Rating	MOSFET	IGBT
Voltage range	20 V–650 V (Si); higher with SiC	600 V–1200 V (to 1700 V+)
Practical switching	up to 100 kHz+	2–20 kHz
Typical uses	DC-DC, load switch, PoL	motor drive, solar, UPS, welder

5. How to choose

• Low voltage (≤ 100 V), high frequency → MOSFET
• 400 V+ and high current → IGBT
• Fast-switching medium power → MOSFET with SiC option
• Match R_DS(on) or V_CE(sat) to your worst-case junction temperature, and always derate.

Related products

• Power MOSFET Series
• IGBT Series
• Bridge Rectifier Series
• Schottky Diode Series