Fast recovery in a hermetic surface-mount package
The Microchip 1N6638US/TR is a fast-recovery standard diode rated for 125 V DC reverse and 300 mA average rectified current, with a reverse recovery time of 20 ns. The SQ-MELF D-5D package is a hermetic, surface-mount ceramic barrel — the same footprint as a DO-213AB but with a full glass seal that holds up to moisture and thermal cycling better than plastic SMD packages.
Parametric profile for snubbing and rectification
Forward voltage is 1.1 V maximum at 200 mA — a typical silicon fast-recovery drop, not Schottky-level, but the 20 ns recovery time means the stored charge clears quickly enough to avoid cross-conduction in a half-bridge leg. Reverse leakage is 500 nA at 125 V, which at 25°C is negligible; at 175°C junction it will rise but stays within the die's thermal budget for pulsed duty. The D-5D package (SQ-MELF) has a metallized end-cap termination that reflows onto the board pad with a standard solder profile; the ceramic body absorbs less moisture than a plastic SOT-23, which matters for long-term storage in uncontrolled environments.