600 V power device technologies for highly efficient power supplies

Switched mode power supplies (SMPS) for target applications covering a wide range from telecom rectifiers through servers to solar inverters or electric vehicle chargers share the need for high efficiencies in order to minimize the overall energy consumption and the total cost of ownership. With the appearance of wide bandgap semiconductors, designers cannot only choose between different devices but also may benefit from using advanced topologies. This work compares the properties of the latest generations of a CoolMOS™ Superjunction (SJ) device with integrated fast body diode, of a CoolSiC™ Silicon-Carbide MOSFET and of a CoolGaN™ E-mode GaN power transistor in the 600 V class. The device behavior is discussed with a view to its use in the AC-DC conversion power factor correction (PFC) stage of a power supply. It is shown how the technology-specific parameters impact the different aspects of the application performance and the choice of topology. This understanding may also act as a guideline for an adequate selection of the best-suited device technology for a given application beyond the scope of AC-DC conversion in power supplies. However, this comparison does not discuss solutions which can address device limitations with the application of dedicated circuitries as, for example, the solution recently proposed for CoolMOS which enables efficiencies close to that of wide bandgap devices [1].