40 V, 80 A N-channel — the conduction-loss floor
The IPB80N04S404ATMA1 is an Infineon OptiMOS N-channel MOSFET rated at 40 V drain-to-source and 80 A continuous drain at 25 °C case temperature. In a 40 V automotive or industrial power rail, this part keeps the I²R heat low enough that the TO-263-3 (D2Pak) footprint on a standard 2 oz copper board can dissipate 71 W at the case without forced air.
Gate charge and drive sizing
Gate charge Qg totals 43 nC at 10 V. For a 100 kHz switching stage, that works out to 4.3 mA average gate current — a standard 1 A driver has plenty of headroom.
175 °C junction — headroom for high-ambient environments
That headroom matters for under-hood automotive or industrial enclosures where ambient hits 105 °C and the self-heating from 80 A peaks pushes die temperature. The threshold voltage Vgs(th) max is 4 V at 35 µA drain, which keeps it fully enhanced with a standard 10 V gate rail.
ROHS3 compliant. No official second-source or drop-in replacement is listed in the Infineon cross-reference for this order code.