Recently, Infineon Technologies AG announced the launch of new devices with a voltage class of 1700 V for its CoolSiC™ MOSFET series. Maximizing the strong physical characteristics of silicon carbide (SiC), this ensures that the new 1700 V surface-mounted devices (SMD) offer superior reliability, as well as low switching and conduction losses. The CoolSiC MOSFETs 1700 V are targeting auxiliary power supplies in three-phase conversion systems such as motor drives, renewables, charging infrastructure and HVDC systems.

Such low-power applications usually operate below 100 W. In these cases, designers very often prefer a single-ended flyback topology. With the new CoolSiC MOSFETs 1700 V in SMD package, this topology is now even enabled for DC-link connected auxiliary circuits up to 1000 V DC input voltage. High efficiency and high reliability auxiliary converters using a single-ended flyback converter can now be implemented in three-phase power conversion systems. This leads to smallest footprints and a reduced bill-of-materials.

“Trench technology of a CoolSiC MOSFET balancing performance and reliability in operation is now available for 1700 V”, said Dr. Peter Friedrichs, Senior Director SiC at the Industrial Power Control Division of Infineon. “It combines the best of SiC properties: low losses with small footprint, in a high voltage SMD package. This helps our customers to significantly reduce the complexity in their auxiliary power supplies”.

The 1700 V blocking voltage eliminates design concerns regarding overvoltage margin and reliability of power supplies. CoolSiC trench technology features lowest device capacitances and gate charges for transistors of this voltage class. The result is a power loss reduction by more than 50 percent and 2.5 percent higher efficiency compared to state-of-the art 1500 V silicon MOSFETs. The efficiency is 0.6 percent higher, compared to other 1700 SiC MOSFETs. The low losses enable compact SMD assembly with natural convection cooling without the need for a heatsink.

The new 1700 V CoolSiC trench MOSFETs are optimized for flyback topologies with +12 V / 0 V gate-source voltage compatible with common PWM controllers. Thus, they do not need a gate driver IC and can be operated directly by the flyback controller. On-resistance ratings are 450 mΩ, 650 mΩ or 1000 mΩ. The new 7 lead D²PAK SMD package offers extended creepage and clearance distances over 7 mm. With that, it fulfills the usual 1700 V application requirements and PCB specifications, minimizing isolation efforts for the design.

CoolSiC MOSFETs 1700 V in D²PAK-7L package are available and in series production. More information please visit www.infineon.com/coolsic-mosfet.