Industrial Automation Magazine India

New MOSFETs 1700 V s optimised for flyback topologies

Published on : Monday 01-06-2020

CoolSiC MOSFET 1700 V SMD enables best efficiency and reduced complexity for high voltage auxiliary power supplies.

Munich, May 2020 – The CoolSiC™ MOSFETs 1700 V s are optimised 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. Infineon Technologies AG complements its CoolSiC™ MOSFET offering with yet another voltage class. Having added 650 V to the portfolio earlier this year, the company is now launching the 1700 V class with its proprietary trench semiconductor technology. Maximising 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.