Active production — sourcing for existing designs
The IRFAF50 is an active-production N-channel HEXFET MOSFET from Infineon Technologies, suitable for current BOM positions and new builds.
900 V rating and 180 nC gate charge — the switching trade-off
The ±20 V maximum gate-source rating is typical for high-voltage MOSFETs and allows a 12 V or 15 V gate drive rail with margin; the 4 V threshold at 250 µA means the device turns on fully with standard logic-level gate drives above 10 V.
Through-hole package and hermetic construction
The through-hole mounting and hermetic MOS construction (N-CHANNEL HERMETIC MOS HEXFET) target high-reliability and military/aerospace applications where the package must withstand moisture and thermal cycling that would crack a plastic-encapsulated device. The 150 W power dissipation rating assumes the case temperature is held at 25°C — in a real system with a heatsink and forced air, the derating curve from the datasheet governs the safe operating area at elevated ambient temperatures.