Schottky rectifier for low-voltage rail protection
The STPS2L40AF is a 40 V, 2 A Schottky barrier rectifier in the SMAflat surface-mount package. It is designed for low forward voltage drop and fast switching, making it a fit for output rectification and freewheeling diodes in low-voltage power supplies, DC-DC converters, and polarity-protection circuits.
Forward voltage and conduction loss
At the rated 2 A forward current, the maximum forward voltage is 430 mV. The low Vf keeps junction temperature rise manageable in the SMAflat footprint, provided the board copper area is sized for the thermal dissipation.
The SMAflat (DO-221AC) package is a surface-mount, leadless variant with flat leads — shorter than a standard SMA, which reduces the parasitic inductance in high-frequency switching nodes. The low profile suits tight-height enclosures, but the exposed pad area is smaller than a standard SMA, so the PCB land pattern should follow the recommended footprint to avoid overheating at sustained 2 A.