600 V, 8 A, 55 ns — PFC and boost stage fit
The STTH806D is a 600 V, 8 A general-purpose fast recovery diode from STMicroelectronics, housed in a TO-220AC through-hole package. Its 55 ns reverse recovery time (trr) places it in the fast-recovery class (≤500 ns, >200 mA Io).
55 ns trr — switching loss anchor
With a trr of 55 ns, the STTH806D limits reverse-recovery charge in continuous-current-mode PFC stages. At 8 A forward current and 1.85 V forward drop (Vf max at 8 A), conduction loss is roughly 14.8 W at full load — the junction temperature ceiling of 175°C sets the heatsink requirement. Reverse leakage is 8 µA at 600 V, a figure that rises with junction temperature and must be factored into standby-loss budgets.
For existing designs, a last-time-buy or a parametric search for a TO-220AC fast-recovery diode with ≥600 V, ≥8 A, and ≤55 ns trr will identify a functional replacement.