The STP7NM50N: The 500 V rating targets offline switch-mode power supplies, power-factor-correction stages, and high-voltage DC-DC converters where the primary-side switch sees rectified mains voltage.
780 mOhm on-resistance and 12 nC gate charge — the switching-loss trade
Maximum on-resistance is 780 mOhm at 2.5 A drain current with 10 V gate drive, and gate charge totals 12 nC at 10 V. For a 500 V device these figures place it in the medium-Rds(on), low-Qg region — conduction loss is moderate, but the light gate charge keeps the driver burden low and switching edges crisp. Input capacitance is 400 pF at 50 V drain-source, which together with the Qg means a standard gate-driver IC or a simple driver transformer can handle the turn-on and turn-off without excessive cross-conduction.
Obsolete — sourcing reality for a discontinued TO-220 MOSFET
ST lists the STP7NM50N as Obsolete. For a BOM line that still calls out this order code, the available channel is independent distribution — new-old-stock or surplus inventory sourced from franchised overstock, contract-manufacturer residue, or verified broker lots. Date-code provenance matters here; any lot surfacing years after the EOL notice should be inspected for traceability and moisture sensitivity.