600 V, 5 A, 25 ns trr — fast-recovery dual diode
Its 25 ns reverse recovery time (trr) at 5 A forward current makes it suited for high-frequency switching circuits where turn-off losses drive the thermal budget. The series-connected pair allows a center-tap or snubber layout with one through-hole device, reducing assembly time versus two separate diodes.
Obsolete — last-time-buy and replacement path
STMicroelectronics lists the STTH506TTI as Obsolete.
The 25 ns trr at 5 A forward current places this diode in the fast-recovery class for 600 V silicon. In a 50–100 kHz PFC or flyback converter, the recovery charge is low enough that the MOSFET turn-on losses stay manageable without a snubber. Reverse leakage at 600 V is 6 µA typ — negligible at room temperature but rises with junction temperature; the 150 °C max junction rating sets the derating ceiling for continuous operation. Forward voltage drop is 3.6 V max at 5 A — this is a trade-off for the fast recovery: expect ~18 W conduction loss per diode at full rated current, so adequate heatsinking on the TO-220AB tab is required.