What this N-channel TrenchMOS™ MOSFET does in the circuit
The D2PAK-7 surface-mount package handles the 300 W dissipation budget when the thermal pad is properly stitched to the board's copper plane.
At 90 A load current with 10 V gate drive, the 3.4 mOhm maximum on-resistance translates to roughly 28 W of conduction loss at the rated current. That is well within the 300 W power dissipation ceiling, but the real-world junction temperature depends on how effectively the D2PAK-7's exposed pad is soldered to a large copper area.
The ±16 V maximum gate-to-source rating gives margin for noisy 12 V and 24 V electrical systems. Nexperia lists no direct successor, so the BUK6C3R3-75C,118 is the current-generation part for new designs.
Surface-mount D2PAK-7 (TO-263-7 variant) with the exposed drain pad on the backside.