New MOSFET By Infineon Enables Better Efficiency For Power Supplies

• Offers superior reliability along with low switching and conduction losses
• Eliminates design concerns regarding overvoltage and power supply reliability

After adding 650 V to its CoolSiC™ MOSFET series earlier this year, Infineon Technologies has now launched the 1700 V class with its proprietary trench semiconductor technology. With strong physical characteristics of silicon carbide (SiC), 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 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 a small footprint 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 a small footprint, in a high voltage SMD package. This helps our customers to significantly reduce the complexity in their auxiliary power supplies”.

Facilitates ease of power supply design

The 1700 V blocking voltage eliminates design concerns regarding overvoltage and power supply reliability. CoolSiC trench technology features lowest device capacitances and gate charges for transistors of this voltage class. This results in a power loss reduction by more than 50 per cent and an increase in efficiency by 2.5 per cent as compared to state-of-the-art 1500 V silicon MOSFETs. The efficiency is 0.6 per cent 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 distance over 7 mm. With that, it fulfils the usual 1700 V application requirements and PCB specifications, minimizing isolation requirements for the design.

CoolSiC MOSFETs 1700 V in D²PAK-7L package is currently in production and available.