650 V, 69 A — the conduction-loss floor in a TO-247
The 38 mOhm max Rds(on) at 34.5 A, 10 V sets the conduction-loss floor for the design — at 10 A the I²R loss is 3.8 W, which the TO-247 package sinks to a heatsink through the exposed back tab. The 400 W power dissipation ceiling at Tc=25 °C is a theoretical limit; real-world dissipation is limited by the junction-to-case thermal impedance and the heatsink's ability to hold the case below 150 °C Tj max.
Gate charge and switching — the driver budget
Total gate charge is 200 nC at Vgs=10 V. At a 100 kHz hard-switching frequency the average gate drive current is 20 mA (Qg × fsw), and the peak current from the driver must deliver the gate plateau in under 100 ns to avoid Miller-turn-on. The input capacitance Ciss is 9800 pF at Vds=100 V — this is the Miller plateau charge and the driver's reactive load. A 10 V gate drive voltage is required for the rated Rds(on); driving below 10 V increases on-resistance and shifts the threshold.