30 ns recovery — why it matters for the switching node
The STTH802D is a standard fast-recovery rectifier from STMicroelectronics, rated for 200 V reverse voltage and 8 A average forward current. Its 30 ns reverse recovery time (trr) is the spec that separates it from slower 200 ns+ recovery diodes — in a continuous-conduction-mode PFC or a 100 kHz+ forward converter, that 30 ns trr keeps the reverse-recovery charge low enough that the MOSFET doesn't see a current spike at turn-on. The forward voltage drop is 1.05 V at the full 8 A rating, which sets the conduction loss budget for the heatsink calculation.
Thermal and leakage — the operating envelope
Junction temperature maxes out at 175°C, which gives headroom for cramped power supplies where the diode shares a heatsink with a hot MOSFET. Reverse leakage is 6 µA at the 200 V rated voltage — low enough that standby losses in a 200 V rail are negligible. The TO-220AC package (through-hole, TO-220-2 outline) is the standard power tab package; the metal tab is the cathode, so the heatsink interface needs an insulating pad if the heatsink is chassis-ground.
ST lists the STTH802D as Active product status.