dv/dt for an SiC MOSFET

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User17640
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Dears,
another question from my side:
What is the maximum dv/dt for an SiC MOSFET turn-on and turn-off? How is it affected by current and temperature?
Thanks for you help
Max P.
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electricuwe
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Hi Max Power, hi Fränce,

dV/dt of SiC Mosfets can be quite high, up to 100 kV/us, for our CoolSiC Mosfet dV/dt can be controlled quite well via the gate resistor.
Compared to IGBTs with Si FWD there is a benefit that there is no steep increase in dV/dt when turning on low currents
dV/dt at turn-off increases with drain current as the current has to charge the output capacitance

In regard to EMI you have to distinguish between dV/dt related noise (usually conducted EMI) and diode recovery related (di/dt of reverse recovery current) noise (usually radiated EMI)

The first will be worse compared to IGBTs, if higher dV/dt is adjusted, the later is expected to improve as the CoolSiC body diode has much better recovery behaviour than a silicon diode.

It is worthwhile to note that you can have benefits in losses, even if you do not adjust higher dV/dt as for IGBTs.

Best regards,
electricuwe

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Fränce
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Hi there,

actually I have a question going into the same direction.
So, I understood that sic will be less expensive on the system side, but what about EMI filters?
Will the fast di/dt & dv/dt lead to more expensive EMI filter?

Have a great evening,
Fränce
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electricuwe
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Hi Max Power, hi Fränce,

dV/dt of SiC Mosfets can be quite high, up to 100 kV/us, for our CoolSiC Mosfet dV/dt can be controlled quite well via the gate resistor.
Compared to IGBTs with Si FWD there is a benefit that there is no steep increase in dV/dt when turning on low currents
dV/dt at turn-off increases with drain current as the current has to charge the output capacitance

In regard to EMI you have to distinguish between dV/dt related noise (usually conducted EMI) and diode recovery related (di/dt of reverse recovery current) noise (usually radiated EMI)

The first will be worse compared to IGBTs, if higher dV/dt is adjusted, the later is expected to improve as the CoolSiC body diode has much better recovery behaviour than a silicon diode.

It is worthwhile to note that you can have benefits in losses, even if you do not adjust higher dV/dt as for IGBTs.

Best regards,
electricuwe
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