800 V, 5 A, 1.15 Ω — the switching MOSFET for flyback and PFC stages
The STP7LN80K5: The 1.15 Ω max on-resistance at 2.5 A and 10 V gate drive gives a conduction loss floor you can budget around in a 85 W dissipation envelope.
TO-220 package — heat sink friendly, board layout forgiving
Through-hole TO-220 with the tab as the drain. The metal tab lets you bolt it to a heatsink with a TO-220 mounting clip or screw, and the 85 W power dissipation at case temperature means you will need that heatsink above a few watts of continuous loss. The supplier device package is TO-220, same as the package/case TO-220-3. The 150°C absolute maximum gives margin for a 105°C ambient inside a sealed PSU enclosure, provided the thermal resistance from junction to ambient is kept under 30°C/W with the heatsink.
Active, ROHS3, and the cross-reference reality
The closest peer in the same voltage class is the STP7N80K5 (SuperMESH5™ series), which carries a 6 A continuous rating and 1.2 Ω Rds(on) at 3 A, 10 V. The STP7LN80K5 has slightly lower on-resistance (1.15 Ω vs 1.2 Ω) at its test condition, but the STP7N80K5 is rated for 1 A more continuous current and dissipates 110 W vs 85 W. They share the same TO-220 footprint and pinout — a drop-in swap is possible if the thermal budget and current margin are re-checked.