The IRFZ44VPBF is an N-channel power MOSFET from International Rectifier's HEXFET series, in a through-hole TO-220AB package. It is rated for a drain-to-source voltage of 60 V and a continuous drain current of 55 A at 25°C case temperature. The 16.5 mOhm maximum on-resistance, specified at 31 A and 10 V gate drive, makes it a fit for medium-voltage switching regulators, DC-DC converters, motor drives, and battery management circuits where conduction losses matter. The 67 nC gate charge at 10 V tells you the driver must deliver enough peak current to switch the FET cleanly at frequency.
NRND — not for new designs
If you have an active design using this order code, plan for a last-time-buy or identify a replacement before the end-of-life notice arrives. The part remains ROHS3 compliant.
The 60 V Vdss is the maximum drain-to-source voltage.
The 115 W maximum power dissipation at case temperature 25°C requires a heatsink for any continuous load above a few amps — the TO-220AB tab is the primary thermal path, and a proper thermal interface to the heatsink is non-negotiable for sustained high-current operation.