47 ns reverse recovery — what it buys the PFC stage
The Infineon IDP15E65D2XKSA1 is a 650 V, 15 A standard recovery diode with a 47 ns reverse recovery time (trr). That trr figure is the key parameter for continuous-conduction-mode PFC boost stages and hard-switched inverter freewheel diodes — it cuts the switching loss tail that a slower 200 ns+ recovery diode would dump into the heatsink. The 2.3 V forward voltage at 15 A is the conduction-loss floor; at 15 A continuous the Vf drop produces about 34 W, so a TO-220 tab bolted to a heatsink is assumed in the thermal budget.
175°C junction — keeps the derating curve on your side
That 175°C ceiling is the limit for the silicon die, not the package tab — the TO-220 case temperature will run lower under steady-state load. In a motor-drive or PFC stage pulling 15 A with a 65°C ambient, the margin between Tj and Tj(max) is what keeps the diode out of thermal runaway. The 40 µA reverse leakage at 650 V is specified at 25°C; expect leakage to rise with temperature, but the 175°C rating gives headroom before the leakage current becomes a self-heating concern.
ROHS3 compliance means it ships lead-free and fits standard reflow or wave-solder profiles without a waiver. The TO-220-2 through-hole package is a mature, widely second-sourced footprint — the tab is compatible with standard clip or screw heatsink mounts.