DO-214AC SMA Schottky, 40 V / 1 A — conduction and switching profile
The STPS140AY is a 40 V, 1 A Schottky rectifier in a DO-214AC (SMA) surface-mount package, part of ST's Q Automotive series. The Schottky barrier gives a forward voltage of 650 mV typical at 2 A, keeping conduction loss low in the rectification path. Rated as fast recovery (≤500 ns, >200 mA), it handles switching frequencies where a standard pn-junction would incur higher reverse-recovery losses. The 12 µA reverse leakage at 40 V sets the off-state power budget — at elevated junction temperature leakage rises, so the thermal design should account for this.
Junction temperature and automotive qualification
The junction temperature range spans -40 °C to 150 °C, a common automotive-grade band suitable for underhood and passenger-compartment environments. The part carries RoHS3 compliance.
The DO-214AC SMA package occupies a standard footprint with a body length of about 4.6 mm and width of 2.8 mm, typical for 1 A Schottky diodes. The cathode is marked by a band on the body; the anode is the opposite end. Reflow profile follows JEDEC J-STD-020 for the package moisture sensitivity level.