85 ns reverse recovery — what it buys the switching stage
The STTH30L06CG-TR is a dual common-cathode fast recovery diode rated 600 V and 20 A per diode. Its 85 ns reverse recovery time (trr) keeps the tail current short enough for continuous-conduction-mode PFC boost stages and hard-switched output rectifiers in the 1–2 kW class.
D2PAK thermal path and board-level fit
The D2PAK (TO-263AB) surface-mount package puts the cathode tab on the large centre pad — the board copper area under that pad sets the junction-to-ambient thermal resistance. The common-cathode configuration shares the tab connection between both diodes, so the same copper island handles the return current from both anodes. This simplifies layout for a centre-tapped secondary or an interleaved PFC stage where the two diodes switch alternately.