Infineon has launched a 650 V hybrid silicon carbide (SiC) and silicon transistor for inverter designs (writes Nick Flaherty).

The CoolSiC Hybrid Discrete for Automotive combines a 50 A fast switching IGBT and a CoolSiC Schottky diode to reduce the cost compared to a pure SiC part but provide the high reliability needed in hard-switching bidirectional inverter designs and onboard chargers (OBCs).

he IGBT enables MOSFET-like turnoff behaviour, outperforming pure silicon architectures as a drop-in replacement with existing silicon driver control chips. This achieves 95-97% system efficiency compared with 99% for an SiC design but at a lower system cost.

Using the SiC diode cuts power losses by 30% and a maximum junction temperature of 175 C in a hard-switching design, leading to lower cooling requirements.

Shenzhen VMAXPower, in China, is using the hybrid device in its next generation OBC/DC-DC system.

“The CoolSiC Hybrid Discrete allows us to simplify driver design, accelerate product development, lower costs and increase system robustness,” said Xu Jinzhu, director of r&d at VMAX.

“The integrated SiC diodes further optimise the EMC characteristics of the system. This results in greater performance benefits and a better price performance ratio in topologies such as totem-pole PFC and DAB.”