Fast-recovery rectifier for high-voltage switching supplies
The Microchip Technology 1N6622US is a standard fast-recovery rectifier diode rated for 660 V DC reverse voltage and 1.2 A average forward current, with a reverse recovery time of 30 ns. This trr places it in the Fast Recovery class (≤500 ns, >200 mA), making it suitable for high-frequency rectification in flyback and forward-converter secondary stages where switching losses matter. Forward voltage is 1.4 V max at 1.2 A, and reverse leakage is only 500 nA at 660 V — the leakage floor stays low enough that self-heating at high line voltage is minimal in a well-laid-out board. The 10 pF capacitance at 10 V, 1 MHz is low enough to avoid significant capacitive coupling in snubber or clamp circuits.
SQ-MELF package — hermetic surface-mount for harsh environments
Housed in an SQ-MELF (A-MELF) surface-mount package, the 1N6622US offers a hermetic ceramic-to-metal seal. This package is standard for high-reliability applications where moisture resistance and thermal cycling endurance are critical — avionics power supplies, downhole instrumentation, and satellite bus converters routinely specify MELF diodes for their solder-joint fatigue life under vibration. The A-MELF footprint is cylindrical with metallized end caps — board layout must account for the barrel geometry to avoid tombstoning during reflow. The package is compatible with standard solder paste stencil apertures for 0.5 mm to 0.8 mm thick boards.