What this 25 ns recovery time buys you in a PFC or flyback
The STTH1302CFP is a 200 V, 6.5 A per diode fast recovery rectifier from ST, configured as a common-cathode pair in the TO-220FP full-pack package. Its 25 ns reverse recovery time keeps switching losses low in continuous-conduction-mode PFC stages or hard-switched flyback converters.
ST lists the STTH1302CFP as obsolete. If you have an active BOM line using this diode, the common-cathode TO-220FP footprint and 200 V / 6.5 A / 25 ns trr window narrows the replacement search — look for a same-pinout ultrafast in the STTH or equivalent family.
25 ns trr — why it matters for the switching loop
A 25 ns reverse recovery time means the diode clears stored charge fast enough to avoid excessive turn-on loss in the MOSFET in a hard-switched PFC or flyback. At 100 kHz switching, each recovery event costs about 25 ns of overlap — at 200 V and 6.5 A that is roughly 32.5 µJ per cycle, or 3.25 W per diode. Compare that to a standard recovery diode (trr > 500 ns) where the loss would be 10× higher. The 6 µA reverse leakage at 200 V is tight enough for junction temperatures up to 175°C, but the leakage doubles roughly every 10°C above 25°C — budget headroom if the heatsink runs hot.
TO-220FP full-pack — field-swap friendly
The TO-220FP full-pack (isolated tab) means no insulating pad or washer needed between the tab and the heatsink — a real time-saver when you are swapping a diode on site without a lab bench. The three through-hole pins are clearly spaced, and the common-cathode pair (pins 2 and 3 tied internally, pin 1 the anode of one diode, pin 3 the anode of the other) is standard enough that a quick continuity check with a multimeter confirms orientation. No hot-air station required; just a soldering iron and a desoldering pump.