30 ns reverse recovery — the switching-loss number
The STTH8T06DI is a fast-recovery epitaxial diode from STMicroelectronics rated 600 V reverse and 8 A average forward current. Its 30 ns reverse recovery time places it in the ultrafast class, suited for continuous-conduction-mode PFC boost stages and secondary-side output rectification in switch-mode power supplies where trr directly sets the turn-off switching loss.
175°C junction — headroom for tight layouts
The junction temperature range extends to 175°C. This provides thermal margin when the TO-220AC insulated package is mounted in a forced-air or conduction-cooled assembly.
STMicroelectronics lists the STTH8T06DI as active.