40 V N-channel HEXFET for automotive power switching
The AUIRFS8408: It is designed for high-current switching applications such as electric power steering, engine cooling fans, and DC-DC converters in 12 V and 24 V vehicle electrical systems.
On-resistance and gate charge — sizing the driver
The 1.6 mOhm Rds(on) at 10 V is the conduction-loss floor at 25°C junction; actual resistance rises with temperature per the normalised curve, so the thermal budget must account for the hot Rds(on) at the operating current. The total gate charge of 324 nC at 10 V determines the gate-driver current needed for the target switching frequency — a 324 nC gate switched at 50 kHz draws about 16 mA from the driver, well within the capability of a standard automotive gate-driver IC.
Junction temperature range and automotive qualification
The 175°C TJ max provides headroom for fault conditions like stalled-motor current or short-circuit events before the silicon reaches its absolute limit.
Lifecycle and procurement posture
The field lists IRFS8408 as a direct cross-reference, which can simplify dual-sourcing or replacement searches.