55 V, 29 A power-switching envelope
The IRFZ34NPBF is an N-channel enhancement-mode MOSFET from Infineon's HEXFET® series, rated for 55 V drain-to-source breakdown and 29 A continuous drain current at 25 °C case temperature. This places it in the 50-60 V, 25-30 A sweet spot for medium-power DC-DC converters, motor-bridge pre-drives, and battery-management disconnect switches.
Conduction loss and gate-drive budget
Maximum on-resistance is 40 mOhm at 16 A drain current with 10 V gate drive. At 29 A full load, the conduction loss (I²R) reaches roughly 34 W before accounting for the Rds(on) positive temperature coefficient — the 68 W case-power limit provides derating headroom for a properly heatsinked installation. Gate charge totals 34 nC at 10 V, and input capacitance is 700 pF at 25 V drain bias. A 10 V gate-drive rail is the recommended minimum for achieving the rated on-resistance; the gate threshold is 4 V maximum at 250 µA, so 5 V logic can turn the device on but with higher Rds(on). The ±20 V Vgs absolute maximum accommodates 12 V automotive gate-drive rails without external clamping.
Temperature grade and package
Operating junction temperature spans -55 to 175 °C, qualifying the part for industrial and automotive under-hood environments where the ambient exceeds 85 °C. The TO-220AB through-hole package with a metal tab provides a low thermal-resistance path to a heatsink — the 68 W dissipation figure assumes the case is held at 25 °C.