SiC power FETs boast super-low 6-mΩ RDS(on)

SiC power FETs boast super-low 6-mΩ RDS(on)


At an RDS(on) value of less than half the nearest SiC MOSFET competitor, a new 6-mΩ device also provides a robust short-circuit withstand time rating of 5 μsec. The new 750-V SiC FET series includes nine new device/package options rated at 6, 9, 11, 23, 33, and 44 mΩ. All devices are available in the TO-247-4L package while the 18, 23, 33, 44, and 60 mΩ devices also come in the TO-247-3L. Complemented by the already available 18 and 60-mΩ devices, this 750-V expanded series provides designers with more device options, enabling more design flexibility to achieve an optimum cost/efficiency trade-off while maintaining generous design margins and circuit robustness.

Gen 4 SiC FETs from UnitedSiC are a ‘cascode’ of a SiC JFET and a co-packaged silicon MOSFET. These together provide the full advantages of wide band-gap technology–high speed and low losses with high-temperature operation, while retaining an easy, stable, and robust gate drive with integral ESD protection. The advantages are quantified by Figures of Merit (FoMs) such as RDS(on)xA, a measure of conduction losses per unit die area. Gen 4 SiC FETs achieve the lowest values in the market at both high and low die temperatures. FoM RDS(on)xEOSS/QOSS is important in hard-switching applications and is half the nearest competitor value. FoM RxCOSS(tr) is critical in soft-switching applications and UnitedSiC device values are around 30% less than competitor parts, rated at 650 V compared with UnitedSiC’s at 750 V.

For hard switching applications, the integral body diode of SiC FETs is superior in recovery speed and forward voltage drop to competing Si MOSFET or SiC MOSFET technologies. Other advantages incorporated into the Gen 4 technology are reduced thermal resistance from die-to-case by advanced wafer thinning techniques and silver-sinter die-attach. These features enable maximum power output for low die temperature rise in demanding applications.

With their latest improvements in switching efficiency and on-resistance, the new UnitedSiC SiC FETs are candidates for challenging, emerging applications. These include traction drives and on- and off-board chargers in electric vehicles and all stages of uni- and bi-directional power conversion in renewable energy inverters, power factor correction, telecoms converters and AC/DC or DC/DC power conversion generally. Established applications also benefit from use of the devices for an easy boost in efficiency with their backwards compatibility with Si MOSFET and IGBT gate drives and established TO-247 packaging.

Pricing (1000-up, FOB USA) for the new 750-V Gen 4 SiC FETs range from $4.15 for the UJ4C075044K3S, to $23.46 for the UJ4SC075006K4S. All devices are available from authorized distributors.

Mike is the founder and editor of, an electronics engineering community/news and project sharing platform. He studied Electronics and Physics and enjoys everything that has moving electrons and fun. His interests lying on solar cells, microcontrollers and switchmode power supplies. Feel free to reach him for feedback, random tips or just to say hello :-)

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