Silicon Carbide Could Improve MOSFET Performance

ON Semiconductor claims that new SiC MOSFETs boost performance and reliability compared to silicon.

SiC MOSFET. (Image courtesy of ON Semiconductor.)

SiC MOSFET. (Image courtesy of ON Semiconductor.)

ON Semiconductor has introduced two lines of wide bandgap silicon carbide (WBG SiC) MOSFETs. The design of these MOSFETs is an improvement over traditional builds and offers levels of performance that ON claims were not possible with silicon MOSFETs.

These MOSFET families are designed for use in a variety of applications, like solar power inverters, onboard charging for electric vehicles, uninterruptible power supplies (UPS), server power supplies and EV charging stations.

The 1200V and 900V N-channel SiC MOSFETs also provide faster switching performance and better reliability when compared to silicon. An intrinsic diode with low reverse recovery charge further reduces power losses, boosts operating frequencies, and increases the power density of the overall system.

The 1200V series is rated at up to 103A (ID max), while the 900V line carries ratings as high as 118A. For applications requiring higher currents, the SiC MOSFETs can be operated in parallel due to their positive temperature coefficient/temperature independence.

SiC MOSFET. (Image courtesy of ON Semiconductor.)

SiC MOSFET. (Image courtesy of ON Semiconductor.)

“If design engineers are to meet the challenging efficiency and power density goals that modern renewable energy, automotive, IT and telecom applications demand, then they require high performance, high reliability MOSFET devices,” said Gary Straker of ON Semiconductor. “ON Semiconductor’s WBG SiC MOSFETs extend performance beyond what was possible with silicon devices, delivering lower losses, higher operating temperatures, faster switching, improved EMI and better reliability.”

Overall, high frequency operation can be enhanced by the MOSFETs’ small chip size, which leads to a lower device capacitance and reduced gate charge (as low as 220nC), reducing switching losses when operating at high frequencies. These enhancements help improve efficiency, reduce EMI when compared with silicon-only MOSFETs, and allow for the use of fewer (and smaller) passive components.