200 V, 15 A common-cathode ultrafast — where it fits in the power stage
The STTH2002CT is a dual-diode array from STMicroelectronics, pairing two 200 V, 15 A ultrafast recovery rectifiers in a common-cathode configuration inside a single TO-220-3 through-hole package.
The 27 ns reverse recovery time is the part's defining parametric. At 200 V blocking and 15 A forward, that trr keeps the reverse-recovery charge low enough that a 100 kHz PFC boost stage runs without excessive turn-on loss in the MOSFET. Compare this to a standard 200 V recovery diode (trr typically 200–500 ns) where the stored charge would double the switching loss and push the junction temperature past the 175 °C rated maximum.
Forward drop and thermal budget at 10 A
That 1.1 V times the average current gives the conduction loss per diode — 11 W at 10 A, before derating. In a 15 A continuous application the junction-to-case thermal path through the TO-220 tab needs a heatsink sized to keep Tj below 175 °C. The 10 µA reverse leakage at 200 V (25 °C) is negligible at room temperature but rises with junction temperature; at 125 °C junction the leakage can increase by an order of magnitude, so the thermal design should budget for that shift.