40 V, 80 A, 6.5 mΩ — a TO-220 switching workhorse, now obsolete
The STMicroelectronics STP95N04 is an N-channel STripFET™ power MOSFET in a through-hole TO-220-3 package. Gate charge is 54 nC at 10 V, and input capacitance measures 2200 pF at 25 V drain-source — numbers that matter for estimating switching losses and driver sizing in a 12 V or 24 V automotive or industrial power stage.
For a BOM that already uses this part, the procurement path is the independent distribution channel — surplus, new-old-stock, or broker-sourced inventory. Any buy should include a visual inspection and parametric verification, especially on date codes more than a few years old.
That is the drive voltage you need to hit the lowest Rds(on) — the part is not characterised at 4.5 V or 5 V logic levels, so a 10 V gate drive rail (or a gate driver that can deliver it) is assumed. The 54 nC total gate charge at 10 V gives a rough switching-energy figure: at moderate frequencies (20–50 kHz) the gate-drive loss is manageable; above 100 kHz the 2200 pF input capacitance starts to eat into efficiency, and a lower-Qg part might be a better fit. For a 40 A continuous rating, the 110 W maximum power dissipation at the case (Tc) means a decent heatsink is non-negotiable — the TO-220 tab needs a thermal interface to anything above a few amps.