1200 V, 5 A, 95 ns trr — PFC and boost diode
The STTH512D is a 1200 V, 5 A fast-recovery epitaxial diode from STMicroelectronics, housed in a TO-220AC through-hole package. Its 95 ns reverse recovery time makes it a fit for hard-switching topologies like power-factor correction (PFC) boost stages, output rectification in flyback converters, and snubber clamping in motor drives.
95 ns trr — switching loss in hard-switched rails
In a continuous-conduction-mode PFC boost at 100 kHz, a slower diode would increase the turn-on loss in the MOSFET and raise the junction temperature of both devices. This part keeps the recovery charge low enough that the designer can stay with a standard gate-drive layout without extra snubber components. Forward voltage is specified at 2.2 V maximum at 5 A, 25 °C junction. That conduction loss — about 11 W at full rated current — means the TO-220AC tab needs a heatsink sized for the duty cycle and ambient. The junction temperature ceiling is 175 °C, so the thermal budget is generous for a 5 A average load in a 50 °C ambient with a modest extruded heatsink.
The base product number is STTH512, covering multiple package variants. The D suffix designates the TO-220AC through-hole version. No official second-source cross-reference appears in the record, but the parametric class — 1200 V, 5 A, fast recovery — is broadly populated across vendors. If dual-sourcing is required, the buyer can qualify an alternate from the same voltage and current class.