170 V, 3 A Schottky in SMAflat — power rail OR-ing and polarity protection
The STPS3170AF is a 170 V, 3 A Schottky rectifier from STMicroelectronics in the low-profile SMAflat package. It is part of the ECOPACK® series, meeting RoHS3 compliance for lead-free assembly. The 170 V reverse voltage rating gives headroom above a 48 V or 60 V bus for OR-ing diodes or reverse-polarity protection — the margin covers transients without avalanche stress. The 3 A average current handles a 2 A continuous load with derating for ambient temperature.
Forward drop and leakage — the thermal trade-off at 3 A
Maximum forward voltage is 820 mV at 3 A — this is the conduction loss floor at rated current. At 2 A the Vf will be lower, but the 820 mV figure is the one to use for worst-case thermal budgeting in a DC-DC output OR-ing or a reverse-battery protection circuit. Reverse leakage is 4 µA at 170 V — a low figure for a 170 V Schottky, which means the diode does not add significant quiescent draw in a battery-powered OR-ing application where the reverse-biased diode sits across the supply rail. Junction temperature range is -40°C to 175°C — the full industrial-automotive temperature band.
SMAflat package — board-fit and reflow profile
The DO-214AC SMAflat package is a surface-mount footprint with flat leads — lower seated height than a standard SMA, which helps in slim PSU or LED-driver designs where the component height is constrained. The flat leads also improve solder-joint inspection access. The ECOPACK® designation means the molding compound and plating are free of halogens and antimony trioxide per ST's green packaging standard.
Active lifecycle and compliance documentation
It is ROHS3 compliant and free of the six restricted substances plus the four phthalates under EU Directive 2011/65/EU. ST provides a full compliance declaration (RoHS, REACH, conflict minerals) for this part. The ECOPACK® series qualification includes a material declaration sheet available from the manufacturer.