SiC devices enable more efficient power electronic modules

According to Cree, its SiC Z-FET mosfets and diodes can be used in advanced power electronics circuits to achieve significantly higher levels of energy efficiency than is possible with conventional silicon devices. Power modules typically combine a number of mosfets and diodes in a single integrated package for high voltage power electronics applications such as three phase industrial power supplies, telecom power supplies and power inverters for solar and wind energy systems. In traditional mosfet packaging technologies, the parasitic inductance of the long leads can limit the switching capabilities of SiC mofets. Cree claims, that by offering bare die alternatives, circuit designers can take full advantage of the switching performance of SiC technology by reducing the effects of the package parasitic inductance. Cengiz Balkas, Cree's vice president and general manager, said: "With the availability of fully qualified SiC mosfets as unpackaged chips, manufacturers of power modules can realise the performance advantages of SiC devices – better high temperature operation, higher switching frequencies and lower switching losses – within the limitations imposed by conventional plastic packaging of discrete devices. The design advantages of implementing SiC power devices in power electronic modules include the ability to achieve higher current and voltage ratings with fewer components, which in turn can enable maximum power density and increased reliability. "Power module manufacturers can now combine Cree's 1200V SiC power mosfet and Schottky diodes in chip form to create an 'all silicon carbide' module design for ultra high efficiency power electronics systems. These new modules provide the proven benefits of silicon carbide – zero reverse recovery losses, temperature independent switching, higher frequency operation with low emi and significantly higher avalanche capability – and deliver switching frequencies that are five to eight times higher compared to conventional silicon solutions. The higher switching frequencies enable smaller magnetic and capacitive elements, thereby shrinking overall system size, weight and cost."