1200 V, 12 A, 100 ns — the fast-recovery rectifier for high-voltage switching
It comes in a D2PAK (TO-263) surface-mount package with the tab as the anode connection, designed for reflow soldering onto a copper pour for thermal management. This part targets power-factor-correction (PFC) stages, flyback converters, and motor-drive boost circuits where the combination of high blocking voltage and fast turn-off cuts switching losses in continuous-current-mode operation.
100 ns trr at 1200 V — what the switching speed buys you
A 100 ns reverse recovery time at a 1200 V blocking voltage is the defining spec for this diode. In a hard-switched PFC stage, that recovery charge directly sets the turn-off loss in the MOSFET and the ringing amplitude on the drain node. A slower diode would force a snubber or a higher-voltage FET; the STTH1212G-TR keeps the recovery soft enough that the EMI filter sees less high-frequency content. The 2.2 V forward drop at 12 A is typical for a 1200 V fast-recovery die — expect about 26 W conduction loss at full rated current, so the D2PAK tab needs a solid thermal path to keep junction temperature under the 175 °C maximum.
For BOM lines that still call out this diode, the supply path runs through independent distribution — surplus stock, last-time-buy inventory, or broker-sourced new-old-stock reels. The D2PAK footprint is common across the STTH1212 family, so a pin-compatible drop-in from the same series may exist, but no cross-reference is documented here. Each reel should be verified against the original date code and moisture-sensitivity level before reflow.