P-channel high-side switch for 12–48 V rails
The Infineon IRF9Z34NPBF is a P-channel HEXFET MOSFET in a TO-220AB through-hole package, rated for 55 V drain-source breakdown and 19 A continuous drain current at 25°C case temperature. P-channel polarity means it can switch the positive rail directly without a dedicated gate-drive boost circuit — useful in battery protection, load disconnect, and reverse-polarity blocking where the load returns to ground. The 100 mOhm maximum on-resistance at 10 V gate drive and 10 A load sets conduction loss at roughly 10 W at full current; that figure drives the heatsink choice and board layout for the 68 W package limit.
Gate threshold voltage maximum is 4 V at 250 µA drain current. The datasheet specifies 10 V gate drive to achieve the rated Rds(on).