NoMIS increases SiC short-circuit withstand time
NoMIS Power, a US-based SiC technology company, has announced a breakthrough in improving the short-circuit withstand time (SCWT) of SiC MOSFETs.
SiC devices have lower short-circuit robustness compared to silicon-based IGBTs which has posed challenges for their use in high-voltage and high-reliability environments, such as industrial drives, electric vehicles, and grid applications.
NoMIS Power's latest advancement significantly extends the SCWT of SiC MOSFETs to a minimum of 5 µs (Fig. 1), compared to the current industry standard of 2-3 µs, with no deleterious effect on specific on-resistance (Ron,sp).
This enhancement greatly improves reliability and unlocks new opportunities for system designers seeking to maximise performance while maintaining fault tolerance, according to NoMIS.
"At NoMIS Power, we have focused extensively on device architecture engineering, leading to a significant advancement in SiC short-circuit withstand time," said Woongje Sung, CTO at NoMIS Power. "We believe this achievement provides valuable advantages to the power electronics community, helping engineers integrate SiC solutions with greater confidence in applications where robustness is critical."
NoMIS Power says its long SCWT devices are well-screened for latent defects and offer easier gate driver desaturation (dSat) design for high di/dt and dv/dt, enabling faster switching frequencies of up to hundreds of kHz.
Initial test results demonstrate a 2X to 4X increase in short-circuit withstand time compared to existing SiC devices, positioning NoMIS Power's technology as a frontrunner in the next generation of power semiconductors. Additionally, when coupled with packaging innovations that impact junction-to-case thermal capacitance, alongside novel thermal management techniques with high heat transfer coefficients, the overall SCWT of the SiC MOSFET can be further improved.
The impact of this innovation extends across multiple industries, including renewable energy, electric transportation, and high-power industrial applications. A longer short-circuit withstand time ensures rugged and reliable performance in critical applications, reinforcing the robustness of SiC-based power systems.
For example, built-in redundancy of the SiC MOSFETs inside power converters, which impacts costs as well as power density, can be reduced. Furthermore, applications sensitive to electromagnetic inference, that cannot solely rely on digital control and sensing schemes to detect and act upon short-circuit events, will now be able to effectively utilize SiC MOSFETs with lower risk.
NoMIS Power will be showcasing this breakthrough technology at APEC 2025, March 16-20, Atlanta.
Pictured above: Figure 1: Drain currents of the NoMIS Power SiC MOSFET and NoMIS Power SiC MOSFET with long SCWT under short-circuit conditions right before failure. Drain currents of the 1.2 kV, 80 mΩ SiC MOSFET (dark blue) and the long SCWT 1.2 kV, 80 mΩ SiC MOSFET (light blue) from NoMIS Power are compared. The measurement for short-circuit was conducted under the following conditions: Rg of 20 Ω, Vgs of 20 V, and a Vds of 800 V.
