40 V, 2 A Schottky in SOD-123F — what it buys the BOM
The STPS2L40ZFY is an automotive-grade Schottky rectifier rated for 40 V reverse voltage and 2 A average forward current, housed in a surface-mount SOD-123F package.
Forward drop and thermal headroom
Forward voltage is specified at 630 mV maximum at 2 A — this is the conduction loss floor that drives the junction temperature rise in a continuous 2 A load. The junction is rated from -40°C to 175°C, so the design must budget the self-heating against the ambient temperature in the enclosure; at 85°C ambient, the remaining 90°C rise allows roughly 1.5 A continuous before derating begins. Reverse leakage is 35 µA at 40 V, which becomes the dominant thermal contributor above 125°C junction — the leakage doubles roughly every 10°C, and at 175°C the leakage current can exceed the forward conduction loss in a lightly loaded rail.
Recovery speed and switching profile
Listed as a fast-recovery type with trr ≤ 500 ns at forward current above 200 mA. This recovery speed suits 50–400 kHz DC-DC converters where the Schottky's low reverse-recovery charge avoids the ringing and switching loss a PN diode would incur. At higher frequencies the junction capacitance becomes the limiting factor; the SOD-123F package keeps parasitic inductance low enough for clean commutation.