Low Vf Schottky for 1 A rail — what that means on the board
The STPS1L30A is a 30 V, 1 A Schottky rectifier in an SMA package. Its 395 mV forward voltage at the full 1 A rating keeps conduction losses low for a surface-mount diode of this size — useful in a flyback catch diode, OR-ing supply, or reverse-polarity protection where the SMA footprint is already assigned. The 200 µA reverse leakage at 30 V is the trade-off for that low Vf; at elevated junction temperature the leakage climbs, so derate the reverse voltage in a hot enclosure if standby current matters.
SMA is a common surface-mount footprint shared across many 1 A Schottky and ultrafast diodes. No heatsink pad underneath — the junction-to-ambient thermal path runs through the solder pads and PCB copper. For a 1 A continuous load, keep the trace width on the cathode side generous to spread heat.