650 V CoolMOS C7 — the switching-loss benchmark
The Infineon IPZ65R065C7XKSA1 is a 650 V N-channel CoolMOS MOSFET in a TO-247-4 package. The 4-pin Kelvin-source TO-247-4 decouples the gate-drive loop from the power loop.
Gate charge and switching — sizing the driver
Total gate charge is 64 nC at 10 V. Input capacitance Ciss is 3020 pF at 400 V Vds. Combined with the 64 nC Qg, this part is designed for fast switching; the datasheet's typical switching-time curves should be reviewed to confirm the external gate resistor value for the target EMI profile.
Thermal and current — heatsink planning
Continuous drain current is 33 A at 25°C case temperature, with a maximum power dissipation of 171 W. In a real 400 V PFC running 1.5 kW, the RMS current through the MOSFET is around 5–6 A, so the 33 A rating provides ample margin — the limiting factor will be the junction temperature rise from the 171 W dissipation ceiling.