120 V, 8.5 A N-channel in a fully isolated TO-220FP
The 180 mΩ maximum on-resistance at 7 A with 10 V gate drive defines the conduction loss for a typical switching application. The TO-220FP full-pack package has a fully molded plastic back — no exposed metal tab — so you can bolt it to a chassis or heatsink without an insulating pad, but the thermal path is through the plastic body only, with a 25 W power dissipation limit at the case.
ST lists the STP14NF12FP as Obsolete. For a design already in production, you will need to source remaining lifetime buys or verified surplus stock through independent distribution.
Wide temperature range and gate drive
Gate threshold voltage is 4 V maximum at 250 µA drain current, and the recommended drive voltage for minimum on-resistance is 10 V — a 12 V or 15 V gate drive rail gives you the full enhancement.
Switching characteristics to budget
These numbers are modest — a typical microcontroller GPIO driving a gate driver IC can switch this MOSFET in the tens of nanoseconds range. The low gate charge keeps driver losses down in high-frequency SMPS or DC-DC converters operating in the 100 kHz ballpark.