The STMicroelectronics STD35P6LLF6 is a P-Channel power MOSFET from the STripFET™ F6 series, built for high-side load switching and DC-DC conversion where a positive supply rail needs to be gated. On-resistance is specified at 28 mOhm maximum when driven with 10 V on the gate at 17.5 A drain current. The 70 W power dissipation limit at the case and a 175 °C maximum junction temperature allow this part to operate in thermally constrained spots like engine-bay electronics or enclosed power supplies, provided the PCB copper or heatsink can extract the heat.
Gate charge and switching behavior
Total gate charge is 30 nC at 4.5 V gate drive, which translates to modest gate-drive losses at switching frequencies typical of load switches and low-frequency DC-DC converters. Input capacitance measures 3780 pF at 25 V drain-source, a figure that matters when sizing the gate resistor and estimating turn-on delay. The gate-source threshold voltage maxes out at 2.5 V at 250 µA drain current. The 4.5 V minimum recommended drive voltage for rated Rds(on) confirms a gate driver is needed.
Housed in the DPAK (TO-252-3) surface-mount package with an exposed tab, the STD35P6LLF6 relies on the PCB copper pour on the drain tab for heat spreading.