150 V, 33 A N-channel HEXFET in the TO-251 IPAK
The Infineon IRFU4615PBF is a 150 V, 33 A N-channel power MOSFET from the HEXFET series, built on planar stripe technology. It is housed in the through-hole TO-251-3 IPAK (TO-251AA) package with short leads, intended for medium-voltage power switching in motor drives, DC-DC converters, battery management, and industrial power supplies.
The on-resistance is specified at 42 mOhm maximum with a 10 V gate-source drive at 21 A drain current. This is the figure to use for steady-state conduction loss in a hard-switched or linear-mode application. The 10 V drive voltage is the recommended gate drive level for minimum Rds(on); driving below that threshold increases on-resistance and shifts the thermal budget. At 33 A continuous drain current (rated at 25°C case temperature), the conduction loss at 42 mOhm is about 46 W. The 144 W power dissipation rating at the case provides headroom, but the junction-to-case thermal path in the IPAK package means the PCB copper area under the tab sets the real-world derating.
26 nC gate charge — switching loss and driver sizing
Total gate charge is 26 nC at Vgs = 10 V. For a 100 kHz switching frequency, the average gate drive current needed is 2.6 mA — well within the capability of a standard gate driver IC. The 1750 pF input capacitance at 50 V Vds gives a rough Miller plateau charge estimate; the 26 nC Qg figure is the one to use for driver power dissipation calculations.
This exceeds the typical industrial -40°C to 150°C envelope and matches the military-temperature-class requirement for avionics, downhole instrumentation, and high-reliability power stages where the ambient near the heatsink can exceed 125°C. The 175°C absolute maximum junction rating means the thermal design must keep TJ below that ceiling under worst-case load.