The AUIRF2805 is an automotive-grade N-channel HEXFET® power MOSFET rated for 55 V drain-source and 75 A continuous drain current. Its headline figure is a maximum on-resistance of 4.7 mOhm at Vgs = 10 V and Id = 104 A — this sets the conduction loss in the steady-state on-period for a motor-drive or DC-DC converter output stage. With a gate charge of 230 nC at 10 V, the switching energy per transition depends on the gate-drive current available; a 2 A gate driver charges the gate in roughly 115 ns, though the actual switching loss in the application also includes the Miller plateau dwell time.
Automotive temperature range and gate drive
The junction temperature range spans -55 °C to 175 °C, covering under-hood and engine-bay thermal profiles where the ambient air can exceed 125 °C on a hot day with the engine running. The 175 °C max junction gives headroom for the self-heating from conduction and switching losses. The gate-source voltage is rated ±20 V absolute maximum — a 12 V or 15 V gate drive rail stays well within this, but a 24 V gate-drive supply would need a series clamp or zener to avoid exceeding the oxide stress limit. Maximum power dissipation is 330 W, though the practical limit in a real board depends on the heatsink and airflow; a TO-220 or similar through-hole package bolted to a 2 oz copper pad on a 4-layer board might handle 50-80 W continuous before the junction hits 175 °C.