MOSFETsIGBTs

MOSFETs and IGBTs are two of the most commonly used power semiconductor devices for switching and amplification in modern electronics. A MOSFET, or metal-oxide-semiconductor field-effect transistor, is a unipolar device whose conductivity between drain and source is controlled by an electric field applied to a insulated gate. An IGBT, or insulated-gate bipolar transistor, combines a MOS gate drive with a bipolar conduction path, allowing it to handle high currents with relatively low on-state voltage drop.

MOSFETs offer fast switching speeds and low on-resistance, especially at lower to moderate voltages. They are widely used in low- to medium-voltage power supplies, DC-DC converters, motor drives, and in applications requiring high-frequency operation. They are gate-driven devices, typically with gate thresholds in the 2–4 V range for logic-level types and up to 10–12 V for standard ones, and they do not rely on minority-carrier storage, which contributes to their speed.

IGBTs are favored for high-voltage, high-current applications where a robust, rugged device is needed. They combine the easy gate drive of a MOSFET with the high-current capability of a bipolar transistor, resulting in higher conduction losses at low frequency but better performance at high voltage levels. IGBTs are common in traction inverters, industrial motor drives, and large power supplies, where switching frequencies are moderate and blocking voltages reach hundreds to thousands of volts.

Choosing between MOSFETs and IGBTs involves considering voltage and current levels, switching frequency, efficiency targets, thermal management, and system cost. Emerging wide-bandgap devices, such as SiC and GaN, are increasingly influencing both technologies, enabling higher efficiency and faster switching in narrow- and wide-bandgap applications.