P-channel 55V 18A — what it handles on the rail
That 55V ceiling covers 48V nominal systems with margin, and the 18A continuous rating supports moderate-load switching in power supplies, load switches, and motor drive half-bridges where a P-channel simplifies the high-side gate drive.
110 mOhm on-resistance — conduction loss budget
Maximum on-resistance is 110 mOhm at 9.6A drain current with 10V gate drive. At 18A the I²R loss hits roughly 36W, but the 57W package dissipation limit at the case means the thermal pad and PCB copper area set the real current ceiling — derate for ambient temperature.
Total gate charge is 32 nC at 10V, which translates to a few mA of drive current at moderate switching frequencies — a basic gate-driver IC or a totem-pole from a PWM controller handles it. Input capacitance is 650 pF at 25V Vds, so the driver sees a light capacitive load; rise and fall times stay tight without a pre-driver.
DPak surface-mount — layout and thermal path
Housed in the TO-252-3 (DPak) package, the IRFR5505TRPBF mounts on the board with the tab as the drain connection and the primary heat path.
ROHS3 compliant.