SiC MOSFET
A SiC MOSFET operates identically to a silicon MOSFET but uses silicon carbide as the semiconductor, giving it a 10× higher breakdown field, ~3× higher thermal conductivity, and much lower switching loss. It's the device of choice for high-efficiency power conversion above 600 V.
SiC's wider bandgap (3.26 eV vs 1.12 eV for Si) allows the depletion region to be much thinner for the same blocking voltage. A thinner depletion region means lower on-state resistance per unit area. The material's thermal conductivity spreads heat rapidly, allowing higher junction temperatures and smaller heatsinks.
In plain terms
Silicon MOSFETs are like sprinters who are fast but struggle with heavy loads. SiC MOSFETs are the decathlon athletes — they handle both high voltage (600–1700 V) and fast switching simultaneously, something silicon can't do without significant compromise.
Why designers use it
- Switch 800 V EV battery packs in traction inverters with < 2 % switching loss.
- Build compact 7 kW on-board chargers for EVs without liquid cooling.
- Replace silicon IGBTs in solar inverters to push efficiency above 99 %.
- Operate in high-temperature downhole oil & gas sensing without derating.
Best for
- EV inverters
- PV inverters
- High-voltage DC-DC
Key specifications
- Vds: 650 V – 3,300 V
- Rds(on): 8 mΩ – 1 Ω
- Switching frequency: 100 kHz – 1 MHz
- Operating Tj: Up to 175 °C
- Gate threshold: 1.5 V – 4 V (Drive 18 V to fully enhance)
When not to use it
- Below 600 V where silicon MOSFETs offer competitive Rds(on) at lower cost.
- When the gate driver and PCB layout can't handle the 50 V/ns dV/dt SiC generates — common-mode noise and EMI become difficult.
Common mistakes
- Using a universal gate-voltage recipe. Select the on-state and off-state gate voltages from the exact manufacturer's recommended operating window, including overshoot and undershoot.
- Treating an absolute maximum gate rating as a recommended drive voltage.
- Copying a silicon-MOSFET driver or PCB layout without checking compatibility with the selected SiC device and switching conditions.
Where you will find it
- A Tesla Model 3 Performance uses SiC MOSFETs in its front inverter: switching the 350 V battery at 20 kHz with SiC's low Qg reduces the per-switching energy loss by 70 % compared to silicon IGBTs, allowing the inverter to be smaller, lighter, and eliminating one cooling circuit from the motor bay.
- A 22 kW AC fast-charger for EVs uses SiC MOSFETs in its PFC front-end and DC-DC converter: the devices' 175 °C junction rating means the charger can run at full power in a 40 °C ambient without derating, unlike silicon which would require forced-air cooling at that temperature.
- A photovoltaic string inverter uses SiC MOSFETs to achieve 99.1 % European efficiency: at the low-load operating points that solar installations spend most of their time at, SiC's near-zero reverse-recovery charge eliminates the switching spikes that would reduce efficiency in a silicon IGBT design.
A short history
Silicon carbide (SiC) MOSFETs were made possible by the development of SiC crystal growth technology in the 1980s and 1990s, largely at Cree Inc. (founded 1987 in Research Triangle Park, NC by John Palmour and others). Cree launched the first commercial SiC power MOSFET (the CMF20120D, 1200 V, 80 mΩ) in 2011. SiC MOSFETs achieve on-resistances 10× lower than silicon MOSFETs of the same voltage rating and can operate at junction temperatures up to 200 °C, enabling the high-efficiency, high-density inverters in electric vehicles and grid storage systems. By 2025, SiC MOSFETs have reached mainstream adoption in EV traction inverters from Tesla, Volkswagen, and BYD.
Good to know
- Silicon Carbide's bandgap (3.26 eV) is 3× silicon's, so SiC MOSFETs withstand higher fields, smaller die, and lower switching loss at the same voltage rating.
- EV chargers and traction inverters moved to SiC starting around 2018 — the Tesla Model 3 was the first mass-produced car with a SiC inverter.
- Driving SiC requires 18 V on the gate (vs 10 V silicon) for full Rds(on) — older silicon-only gate drivers don't have the headroom.