880 V / 1 A fast recovery — the switching envelope
The Microchip Technology 1N6623/TR is a standard fast recovery diode rated 880 V DC reverse and 1 A average rectified current, with a reverse recovery time of 50 ns. The 880 V blocking voltage and 1 A forward current define the BOM line's voltage-current envelope — a 1 A rail at up to 880 V peak inverse voltage stays within the device's safe operating area without derating for repetitive peaks.
50 ns trr — what it means for the switching node
The 50 ns reverse recovery time places this diode in the fast-recovery class (≤500 ns, >200 mA). At 50 ns, the stored charge clears quickly enough that a 100 kHz hard-switched converter sees minimal reverse-recovery loss in the diode — the switching node rings less and the MOSFET's turn-on stress drops. Reverse leakage is 500 nA at the full 880 V blocking voltage — negligible at 25°C, but leakage doubles every 10°C junction rise. At 125°C junction the leakage current approaches the microamp range, adding to the thermal budget.
Axial through-hole on tape and reel
The 1N6623/TR ships in the standard A, Axial through-hole package, supplied on tape and reel (TR suffix). The axial leads insert into plated-through holes on the PCB — the lead bend radius and hole-to-hole spacing follow the standard DO-41 footprint. The tape-and-reel format feeds into automatic insertion machines for high-volume assembly; the reel quantity is the standard axial reel count for this package family. The 10 pF junction capacitance at 10 V, 1 MHz is low enough that the diode does not load the switching node with significant capacitive charge — in a 100 kHz flyback snubber, the added capacitance is negligible compared to the transformer leakage inductance.