400 V, 1 A fast recovery rectifier — 30 ns trr in a DO-15 axial package
The STTH1R04Q from STMicroelectronics is a 400 V, 1 A fast recovery rectifier with a 30 ns reverse recovery time, housed in a DO-204AC (DO-15) axial-lead through-hole package. It is designed for high-frequency switching applications where reverse recovery charge and switching losses must be minimised — typical roles include boost diodes in PFC stages, output rectifiers in flyback converters, and snubber clamps across switching devices.
The 30 ns reverse recovery time is the key switching parameter. In a continuous-conduction-mode PFC boost stage, a 30 ns trr keeps the diode turn-off loss low enough that the heatsink stays small and the MOSFET or IGBT does not see a hard-recovery current spike at every switching cycle. The forward voltage drop is 1.5 V max at 1 A — a reasonable trade-off for the fast recovery characteristic. Reverse leakage is 5 µA at 400 V rated reverse voltage, and the junction temperature rating goes to 175°C max, so the part can sit on a hot PCB near a heatsink or transformer without derating prematurely.
The DO-15 axial package is a common through-hole form factor, so cross-shopping a same-function fast recovery diode in the same footprint is straightforward.