Device identity and headline ratings
The AUIRF4104STRL is an N-channel HEXFET power MOSFET rated 40 V drain-source and 75 A continuous drain current, housed in a D2PAK (TO-263) surface-mount package.
On-resistance, gate charge, and temperature — the design-in drivers
Total gate charge is 100 nC at 10 V, so a gate driver sourcing 1 A charges the gate in about 100 ns — fast enough for switching frequencies in the tens of kHz, but the driver's peak current and loop inductance need attention to avoid Miller plateau ringing. The junction temperature range spans -55°C to 175°C, which covers automotive under-hood and industrial ambient extremes — the 175°C ceiling gives headroom for derating the 140 W power dissipation at elevated case temperatures.