Hi-voltage SiC transistor aimed at electric vehicle chargers

May 15, 2014 // By Christoph Hammerschmidt
With what the vendor claims to be the first commercially available silicon carbide (SiC) 1200V MOSFET, semiconductor manufacturer Cree offers a switching transistor with a low RDS(on) of 25 mOhm. Cree is targeting charging systems for electric vehicles, and also high voltage DC/DC converters, induction heating systems and medical CT applications.

Based on the company's C2M SiC MOSFET technology, the C2M0025120D has a pulsed current rating (I DS Pulse ) of 250A and a positive temperature coefficient, providing engineers with greater design flexibility to explore new design concepts. The high I DS Pulse rating makes the device suitable for pulsed power applications, and the positive temperature coefficient allows the devices to be paralleled to achieve even higher power levels.

The higher switching frequency of the SiC MOSFET enables power electronics designers to reduce the size, weight, cost, and complexity of power systems. For medical applications, such as CT systems, Cree's C2M MOSFETs claim a 5X reduction in switching losses and enable much higher power density. Combined with the lower switching losses, the added benefit of low R DS(on) greatly improves the thermal characteristics and can potentially even eliminate system fans, resulting in quieter and more cost effective medical imaging systems.

Cree has also demonstrated that, by implementing the C2M0025120D in a PV string-inverter, it is possible to develop a highly efficient and compact 50 kW grid-tied solar inverter with a power to weight ratio of 1 kW/kg. This results in a string inverter that is significantly more efficient and half the weight and size of the state-of-the-art commercial 50 kW systems available today. Additionally, for rooftop PV inverters, the smaller size and lighter weight greatly reduce the installation costs.

Cree offers several tools to help engineers get started with their next designs, including full reference designs of recommended SiC MOSFET gate driver circuits. CRD-001 gate driver boards provide a way to quickly evaluate the C2M0025120D device using industry standard components. The MOSFETs are also compatible with  industry standard gate drivers from a broad range of companies including TI, Avago, and IXYS.