620 V N-channel in DPAK — switching loss and conduction budget
The 70 W power dissipation rating at the case gives the thermal budget for the DPAK package — the actual junction-to-ambient thermal resistance depends on the copper area on the drain tab pad.
Gate charge and drive requirements
Total gate charge is 14 nC at 10 V, which keeps the drive current modest even at switching frequencies above 100 kHz — a 14 nC gate switched at 100 kHz draws 1.4 mA average from the driver. The input capacitance is 450 pF at 50 V drain bias, so the gate-drive loop inductance and the driver's peak current capability set the turn-on and turn-off edge rates. The gate-source threshold voltage is 4.5 V maximum at 50 µA drain current, meaning a 10 V drive rail is needed to achieve the rated Rds(on); a 5 V logic-level gate drive will not fully enhance the channel.
Package and mounting — DPAK thermal interface
The TO-252-3 (DPAK) surface-mount package has a drain tab that is the primary thermal path.