40 V, 500 mA Schottky in SOD-123 — what it handles
The STPS0540ZY is a 40 V, 500 mA Schottky barrier rectifier in the SOD-123 surface-mount package, part of ST's Q Automotive series. It is designed for low-voltage, high-frequency rectification in automotive and industrial power supplies, reverse-polarity protection, and freewheeling diodes in DC-DC converters. The forward voltage drop is 500 mV maximum at 500 mA forward current. Reverse leakage is 40 µA at the 40 V rated reverse voltage.
Junction temperature and automotive qualification
The 150°C junction rating supports the thermal margin needed for engine-bay and transmission-control modules.
SOD-123 is a small outline plastic package with a single cathode tab on one end — the copper pad area under the cathode sets the junction-to-ambient thermal resistance. The surface-mount body suits automated pick-and-place and reflow soldering.
It is ROHS3 compliant, with no exemptions that would restrict its use in new European or North American automotive builds.