990 V blocking with 60 ns recovery — what it means for the circuit
The 1N6624 is a fast-recovery rectifier rated for 990 V DC reverse voltage and 1 A average forward current, with a reverse recovery time of 60 ns. That 990 V rating gives comfortable margin on an 800 V DC bus — the diode stays in blocking even during line transients that push the rail above nominal. The 60 ns trr places it well inside the fast-recovery class (≤500 ns), which matters when the diode must snap off quickly in a continuous-conduction-mode PFC stage or a high-voltage snubber. Forward drop is 18 V maximum at 500 mA — that is high compared to a standard recovery diode, but typical for a fast-recovery part with this voltage rating. The power dissipated at 1 A average is manageable in the axial package as long as the lead length provides adequate heatsinking to the board.
Active production — no end-of-life concern for BOM planning
This is the full Mil-spec temperature grade — the diode operates reliably in engine bays, avionics bays, and outdoor telecom enclosures without derating concerns at the hot end.
Package and mounting — axial lead for through-hole assembly
The 1N6624 comes in the standard A, Axial package (also referred to as A-PAK). It is a through-hole device, so it inserts into plated through-holes on the PCB and is wave-soldered or hand-soldered. The axial lead form factor is common for high-voltage rectifiers where creepage distance between anode and cathode matters — the body length keeps the terminals separated. For low-volume production or prototyping this is fine; for high-volume pick-and-place you would need to verify whether the supplier can provide a taped option or if a reel-compatible sibling exists.
Low capacitance for high-frequency snubbing
The diode exhibits 10 pF of capacitance at 10 V reverse bias, measured at 1 MHz. That low junction capacitance means the diode does not load the switching node significantly in a snubber or clamp application — it will not ring with the stray inductance at frequencies where a higher-capacitance part would. Reverse leakage is only 500 nA at 900 V reverse voltage. At the full 990 V rating the leakage will be slightly higher, but the sub-microamp figure confirms the junction is clean — no excessive leakage that would heat the diode in a lightly loaded standby rail.