800 V MDmesh N-channel — what this part is for
With an 800 V drain-source breakdown and 5 A continuous drain current, it slots into flyback converters, PFC stages, and auxiliary power supplies where the primary-side switch sees a rectified 400 V DC bus plus reflected voltage margin.
The on-resistance is specified at 1.15 Ohm maximum with 2.5 A drain current and 10 V gate drive. That 10 V drive level is the recommended operating point for minimum RDS(on); the gate threshold is 5 V maximum at 100 µA, so a standard 12 V or 15 V gate-drive rail from a PWM controller or driver IC lands squarely in the sweet spot.
TO-220 Full Pack — thermal and mechanical fit
The TO-220FP body is the fully moulded, isolated-tab variant. No metal tab exposed — the mounting hole is through the plastic, and the back of the package is the resin over the die pad. That means the 25 W power dissipation limit (at case temperature) is the ceiling, and the thermal path to the heatsink goes through the plastic, not a metal tab. Expect higher junction-to-case thermal resistance than a standard TO-220; the trade-off is no isolation hardware. For a 5 A, 800 V part in an offline supply, the full-pack package is common where the heatsink is chassis-grounded and you want to skip the sil-pad or mica washer.
Active status — no LTB risk
ST's MDmesh portfolio is broad, and this is a current mainstream voltage/current tier.