Why Review Silicon Carbide

Silicon carbide promises higher efficiency and smaller converters, but the datasheet only tells part of the story. This review examines Silan's 1200 V SiC MOSFETs from the perspective of an FAE who supports customers through design-in and bring-up, focusing on on-resistance, switching behavior, packaging and practical layout.

On-Resistance and Loss

Silan SiC MOSFETs span a range of on-resistance values from about 13.5 milliohm upward, which lets designers trade cost against conduction loss. The critical detail is that on-resistance rises with temperature, so the hot value at your junction temperature, not the 25 C figure, determines conduction loss. On evaluation hardware, the measured conduction loss tracked the datasheet hot value closely, confirming that a thermal-aware loss estimate is reliable. Combined with the low switching loss of SiC, this yields high efficiency across the load range.

Switching Behavior

SiC has no tail current, so the turn-off transition is clean and switching loss is low. That enables higher switching frequency, which shrinks magnetics and improves power density. The trade-off is that fast switching excites parasitic inductance, so gate-loop and commutation-loop layout dominate ringing and overshoot. Keeping loops short and tuning the gate resistor are the main levers, and the results are excellent once the layout is right.

Packaging and the Four-Lead Advantage

Silan offers its 1200 V SiC MOSFETs in a four-lead TO-247 package with a Kelvin source, and in an HSOP package. The four-lead arrangement removes source inductance from the gate loop, which is a genuine advantage for SiC because that inductance is what turns fast switching into ringing. In our tests, the four-lead part produced noticeably cleaner gate waveforms and lower overshoot than a comparable three-lead device at the same gate resistance. For a designer new to SiC, choosing a four-lead package is one of the simplest ways to get a stable design.

Gate Charge and Drive

Gate charge for these parts ranges from about 100 to 224 nC, so the driver must source and sink real current to switch quickly. A stiff driver, a short gate loop and a gate resistor tuned to your EMI target are the essentials. A negative off-state supply improves robustness at high dv/dt, and the Kelvin source makes the gate signal cleaner.

Applications

The 1200 V SiC MOSFETs fit high-frequency, high-efficiency converters: photovoltaic string inverters, EV charging stages, on-board chargers, energy-storage converters and industrial power supplies. In these applications, the combination of low on-resistance and low switching loss raises efficiency and lets the magnetics shrink, which improves power density in a compact enclosure. Where cost is the dominant constraint and the frequency is modest, a silicon IGBT remains the economical choice.

Solar and Storage

In a solar inverter, SiC in the boost stage raises the MPPT switching frequency, shrinking the boost inductor and improving tracking. In storage converters that run in both directions, SiC keeps loss low across the whole operating range, which matters for round-trip efficiency. These are the applications where the review found SiC to be most compelling.

Layout Practice

SiC rewards a disciplined layout. Keep the DC-link capacitor close to the device with a low-inductance connection, size the gate resistor to control the edges within the EMI budget, and measure overshoot at the device terminals rather than at the bus. Because the device switches faster than silicon, the commutation loop matters more, not less. In our tests, a tight loop and a moderate gate resistor produced clean waveforms with comfortable margin.

Conclusion

Silan's 1200 V SiC MOSFETs deliver on their promises: low on-resistance, clean fast switching and a four-lead package that makes the fast switching manageable. In our evaluation they were straightforward to design in and reliable on the bench. For new high-frequency, high-efficiency converters, they deserve to be on the shortlist, and BeiLuo's authorized stock and FAE support make evaluation easy.