ST schedules volume production of silicon carbide MOSFETs for 200C operation

March 13, 2014 // By Graham Prophet
STMicroelectronics has announced that it will soon begin production of the first device in a family of silicon-carbide high-voltage MOSFETS, and asserts that his makes it “among the first” companies to commercialise SiC power MOSFETs, with a 200°C rating for more efficient, simplified designs.

Major features of SCT30N120 include; On-state resistance (RDS(ON)): 80 mΩ typ. at 25°C, and ≤100mΩ typ over the entire temperature range to 200°C; low turn-off energy and gate charge (ensures efficient, high-speed switching); and leakage current lower than 10 μA typ (enhances system energy efficiency and reliability, compared to other structures based on the same material).

The transistors have a very fast intrinsic and robust body diode (saves an external freewheeling diode for cost/size reduction); and use simplified gate drive circuitry (reduces costs of network driving).

With what ST terms a high-temperature performance edge, ST is positioning the FETs as enabling power supply designers to drive up energy efficiency in applications such as solar inverters and electric vehicles, enterprise computing, and industrial motor drives.

SiC properties help save at least 50% of the energy normally lost in conventional silicon power transistors. The devices can also be physically smaller for a high breakdown voltage.

SiC MOSFETs will be used in solar inverters, as an alternative for conventional high-voltage silicon IGBTs (Insulated Gate Bipolar Transistor), with no special drive circuitry required. By operating at higher frequencies than IGBTs, SiC MOSFETs allow designers to miniaturise other components in the power supply.

In electric vehicles, SiC is expected to help significantly increase the energy efficiency and reduce the size of traction systems. The US DRIVE Electrical & Electronics Technical Team, a partnership between industry and the US government’s Department of Energy, is calling for energy losses to be approximately halved by 2020 while also reducing size by more than 20%. The team’s roadmap specifies wide bandgap semiconductors – in other words, SiC technology – as a focus for R&D to increase power-converter efficiency and make the device tolerate higher operating temperatures more safely. The increased temperature capability of ST’s SiC devices (200°C), compared to ordinary silicon and competitors’ SiC MOSFETs, will help simplify vehicle cooling system design.

ST’s new 1200V SiC power MOSFET, the