Infineon Technologies AG has unveiled what is claimed to be a revolutionary silicon carbide (SiC) MOSFET technology allowing product designs to achieve previously unattainable levels of power density and performance. Infineon’s CoolSiC MOSFETs offer a new degree of flexibility for increasing efficiency and frequency. They will help developers of power conversion schemes to save space and weight, reduce cooling requirements, improve reliability and lower system costs.
"For more than twenty years, Infineon has been at the forefront of developing SiC solutions which address demands for energy savings, size reduction, system integration and improved reliability," said Dr. Helmut Gassel, President of Infineon's Industrial Power Control Division. "Infineon has manufactured millions of products containing SiC devices, while our Schottky diode and J-FET technologies have allowed designers to achieve power density and performance not possible with conventional silicon. The strategy has now taken a significant step forward encompassing power MOSFETs that raise the benefits available from SiC technology to a new level, which has never before been possible."
The impact of SiC MOSFET functionality is truly impressive. Power conversion schemes can operate at triple or more the switching frequency in use today. This leads to benefits such as reducing the copper and aluminum materials used in magnetics and system housing, facilitating smaller and lighter systems for less transportation effort and easier installation. New solutions supporting energy savings will be realized by the designers of power conversion applications. These applications can harness performance, efficiency and system flexibility in a completely new dimension.
The new 1200V SiC MOSFETs have been optimized to combine reliability with performance. They operate with 'benchmark' dynamic losses that are an order of magnitude lower than 1200V silicon IGBTs. This initially supports system improvements in applications such as photovoltaic inverters, uninterruptible power supplies or charger/storage systems, while later configurations will also extend support to industrial drives.
The MOSFETs are fully compatible with the +15V/-5V voltages typically used to drive IGBTs. They combine a benchmark threshold voltage rating (Vth) of 4V with short-circuit robustness required by the target applications and fully controllable dv/dt characteristics. Key benefits over Si IGBT alternatives include temperature-independent switching losses and threshold-voltage-free on-state characteristics.
The culmination of many years of experience of SiC semiconductor development, the new MOSFETs are based on a state-of-the-art trench semiconductor process and represent the latest evolution of Infineon's comprehensive family of CoolSiCtechnologies. This family includes Schottky diodes and 1200V J-FET devices and a range of hybrid solutions that integrate a Si IGBT and SiC diode in a module device.
The first discrete 1200V CoolSiC MOSFETs feature on-resistance (R DS(on)) ratings of just 45mÎ©. They will be available in 3-pin and 4-pin TO-247 packages targeted at photovoltaic inverters, UPS, battery charging and energy storage applications. Both devices are ready for use in synchronous rectification schemes thanks to the integration of a commutation robust body diode operating with nearly zero reverse recovery losses. The 4-pin package incorporates an additional (Kelvin) connection to the source, which is used as a reference potential for the gate driving voltage. By eliminating the effect of voltage drops due to source inductance, this further reduces switching losses, especially at higher switching frequencies.
Infineon has also announced 1200V 'Easy1B' half-bridge and booster modules based on the SiC MOSFET technology. Combining PressFIT connections with a good thermal interface, low stray inductance and robust design, each module is available with R DS(on)rating options of 11mÎ© and 23mÎ©. Infineon will start sampling for target applications in the second half of 2016, with volume production planned for 2017.