The 1N6624/TR is a 990 V reverse voltage, 1 A average rectified current fast recovery diode from Microchip Technology, with a 60 ns reverse recovery time (trr) that places it in the Fast Recovery class (≤500 ns, >200 mA Io). The 60 ns trr means the diode switches off quickly enough to keep the stored charge from ringing the snubber or the transformer leakage inductance in a 100-200 kHz flyback or forward converter — the recovery is the dominant loss term in the output rectifier at those frequencies. Forward voltage is 1.55 V max at 500 mA — the conduction loss at 1 A average is roughly 1.5-1.6 W, which the axial lead package must sink through the board copper or a clip-on heatsink if the ambient is above 85°C.
Junction temperature and leakage across the operating range
Capacitance is 10 pF at 10 V reverse bias, 1 MHz — this is low enough that the capacitive switching loss at 200 kHz is under 5 mW, negligible compared to the conduction and recovery losses.
The tape-and-reel packaging (TR suffix) suits automated pick-and-place assembly for volume builds.