150V 2.5A N-channel in a TO-205AF can
The IRFF9221 is an N-channel enhancement-mode MOSFET from Infineon's HEXFET series, rated for 150 V drain-source and 2.5 A continuous drain current in a through-hole TO-205AF package. The 150 V breakdown gives headroom for 48 V, 72 V, or 100 V bus rails — the derating margin covers switching transients without avalanche stress. 2.5 A continuous rating suits moderate-load switching in DC-DC converters, solenoid drivers, and auxiliary power stages where a TO-220 would be oversized.
20 W power dissipation in a metal-can package
Maximum power dissipation is 20 W — this is the thermal budget at the case, not the junction. The TO-205AF metal can conducts heat through the mounting flange; a heatsink or PCB copper area is needed to stay inside the SOA at continuous 2.5 A. The through-hole mounting (TO-205AF) provides a lower thermal resistance path to the heatsink than a surface-mount equivalent — the metal tab can be bolted or clamped directly.