The STPS140Z is a 1 A, 40 V Schottky rectifier from STMicroelectronics in a SOD-123 surface-mount package. Schottky construction gives it a fast recovery time (under 500 ns at >200 mA) and a low forward voltage of 550 mV at the full 1 A rated current. That low Vf keeps conduction losses down in low-voltage rails and OR-ing applications. The 40 V reverse rating gives headroom for 24 V and 12 V buses, and the 150°C maximum junction temperature suits industrial and automotive ambient conditions.
Forward drop and thermal margin
At 1 A forward current the 550 mV drop is about half what a standard pn-junction rectifier would show at the same current. That directly reduces self-heating in the SOD-123 body, which has limited thermal mass. If you are pushing 1 A continuous in a warm enclosure, check the junction temperature against the 150°C limit—derating for ambient and PCB copper area is worth the calculation. The 40 µA reverse leakage at 40 V is typical for a Schottky of this voltage class and should be factored into standby power budgets.
SOD-123 footprint and assembly
SOD-123 is a standard small-signal diode footprint, compatible with common pick-and-place and reflow profiles. No special bake or handling beyond standard MSL precautions applies.
The base product number is STPS140, so cross-references within that family share the same die and package options.