60 V, 120 A, 3 mOhm — the conduction-loss floor
The IRFP3206PBF is an Infineon HEXFET N-channel power MOSFET in a TO-247AC through-hole package.
The 3 mOhm Rds(on) at 75 A is the lowest on-resistance tier in the 60 V HEXFET family; at full 120 A load the I²R loss is 43 W, which the 280 W power-dissipation rating can handle with an adequate heatsink. The 170 nC total gate charge at 10 V means the gate driver must supply 17 mA average at 100 kHz switching frequency — a standard 2 A gate-driver IC has ample headroom, but the gate-drive loop inductance must be kept under 10 nH to avoid ringing at turn-on.