Low on-resistance Silicon Carbide MOSFET Targets EV Drives

Wolfspeed, (part of Cree and in the process of being acquired by Infineon) has introduced a silicon carbide (SiC) a MOSFET rated for 196 A, with a 900V rating and with 10 mΩ on-resistance; the current rating is of continuous drain current at a case temperature of 25°C.

The MOSFET is initially available in bare die form as part number CPM3-0900-0010A, and is currently available for purchase from SemiDice. Wolfspeed expects to release the associated discrete device in a 4L-TO247 package (C3M0010090K) in the coming weeks (as of January 2017). This package has a Kelvin-source connection that allows engineers to create designs that maximize the benefits of SiC's superior speed and efficiency. Commercially qualified and rated for a maximum operating temperature of 175˚C, Wolfspeed's new chip offers high-reliability in harsh environments, like those found in vehicle drive-trains.

This device enables the reduction of EV drive-train inverter losses by 78% based on EPA combined city/highway mileage standards. This efficiency improvement offers designers new options in terms of range, battery usage, and vehicle design.

"With the commercial release of the 900V 10mΩ device, electric vehicles can now reap the benefits of SiC in all aspects of their power conversion," said John Palmour, CTO of Wolfspeed. "With the continued expansion of our Gen3 MOSFET portfolio in new package options, our devices can now support significant efficiency improvements in onboard chargers, offboard chargers, and now EV drive trains."

Wolfspeed adds that it recently supplied Ford Motor Company – in a collaboration with the U.S. DoE –with a full-SiC, 400A power module designed around the 900V, 10mΩ chip. The module, designed and produced by Wolfspeed, contains four MOSFETs connected in parallel to achieved an effective on-resistance (Rds(on)) of 2.5 mΩ. Wolfspeed engineers have since demonstrated the capability to use these chips to create an 800A, 1.25 mΩ module.