Rohm has announced a 4th generation of 1.2kV silicon carbide mosfets, honing them for driving the traction motors of electric vehicles as well as industrial equipment power supplies.

“For power semiconductors, there is often a trade-off between lower on-resistance and short-circuit withstand time,” said the company. “Rohm was able to improve this relationship and reduce on-resistance per unit area by 40% without sacrificing short-circuit withstand time.”

This came from further work on its double trench structure, created to improve long-term reliability by minimise electric field concentration in a trench gate.

Rohm-1200V-Gen4-SiC-mosfet-energy-graph-655Gen 4 also reduces parasitic capacitance – Cgs and Cgd from the gate oxide film and Cds from the parasitic diode – contributing to 50% lower switching loss over Rohm’s third generation, it said.

Bare chip samples are available from this month, with discrete packaged devices to follow.