170 V, 2 A Schottky — what the ratings mean for the BOM
The STPS2170AF is a 170 V, 2 A Schottky rectifier from STMicroelectronics in the ECOPACK series. The 170 V reverse voltage covers 48 V and 72 V rails with margin, and the 2 A average forward current suits low-to-moderate power supplies, polarity protection, and freewheeling diodes in DC-DC converters. Forward voltage is 820 mV maximum at 2 A — this is the conduction loss floor. At 2 A, the diode dissipates about 1.64 W; the SMAflat package's thermal resistance to ambient must keep the junction below 175 °C.
Switching speed and leakage profile
Classified as Fast Recovery (≤ 500 ns, > 200 mA), this Schottky's majority-carrier structure inherently switches faster than a PN-junction recovery diode — the 500 ns ceiling is a classification boundary, not the device's actual turn-off time. In practice, a Schottky of this voltage class switches in tens of nanoseconds, making it suitable for switching frequencies in the 100 kHz range. Reverse leakage is 2.8 µA at 170 V, 25 °C junction. Leakage doubles with every 10 °C rise; at 125 °C it will be roughly 45 µA, still acceptable for most power circuits but worth derating in high-temperature or high-impedance bias applications.
Housed in a DO-214AC (SMA Flat Leads) package, the STPS2170AF is a surface-mount device with a low-profile, flat-lead form factor. The SMAflat footprint is a drop-in replacement for standard SMA packages on most layouts, but the lead bend height differs — confirm the solder-paste stencil aperture for the flat-lead geometry to avoid open joints. Junction temperature range is -40 °C to 175 °C, covering industrial and automotive under-hood environments. The 175 °C maximum junction is the absolute ceiling; the thermal design should target a junction temperature below 150 °C for long-term reliability.