The STTH5R06DJF-TR is a 600 V, 5 A fast-recovery epitaxial diode from STMicroelectronics, built for hard-switched topologies where reverse recovery charge adds to switching loss. Its 55 ns reverse recovery time (trr) keeps the diode from conducting backward during the MOSFET turn-on transition, which directly cuts the current spike and the associated EMI signature in a continuous-conduction-mode PFC boost stage or a flyback clamp.
5 A continuous at 600 V — derating and thermal budget
Rated 5 A average rectified current at a junction temperature up to 175°C. The forward voltage drop is 2 V at 5 A — that is 10 W conduction loss at full rated current, so the PowerFlat 5x6 exposed pad needs a decent copper area on the PCB to keep the junction below the 175°C ceiling. Reverse leakage is 60 µA at 600 V, which is negligible at room temperature but climbs with junction heat; budget the leakage term in the thermal calculation if the diode runs hot.
PowerFlat 5x6 — footprint and rework
The 8-PowerVDFN package (PowerFlat 5x6) is a 5 mm × 6 mm QFN-style body with an exposed die attach pad. The pad is the main thermal path — solder it to a copper pour with at least a few vias to inner layers. The part is MSL-sensitive like any QFN; bake the reel if the moisture barrier bag is punctured. Under a hot-air station the small body reflows fast; the trick is getting the paste volume right on the pad so the part self-centres without voiding the thermal interface.