TO-205AF package and board integration
The IRFF9231 comes in a TO-205AF through-hole package, a metal-can variant that requires a 0.100-inch (2.54 mm) pitch hole pattern on the PCB. The metal tab is the drain terminal and must be soldered to a copper island for thermal management — the 25 W power dissipation demands a heatsink or adequate board copper area to keep the junction below the rated maximum.
Rated 150 V drain-source and 4 A continuous drain current, this N-Channel MOSFET is sized for 48 V and 72 V bus systems with margin for transients. The 4 A rating is the DC limit at 25 °C case temperature — derate by the RθJC thermal resistance for actual operating conditions, especially when dissipating the full 25 W. The N-Channel polarity means the load connects between the drain and the positive supply rail, with the source tied to ground through the sense resistor or directly. Gate drive must be referenced to the source pin — a bootstrap or isolated supply is needed for high-side switching above 20 V.
Active lifecycle — no end-of-life risk
As an Infineon Technologies part, the IRFF9231 benefits from the company's established manufacturing and quality systems.