170 V, 3 A — the switching loss floor
The STPS3170UF is a 170 V, 3 A Schottky rectifier in the SMBflat package, part of ST's ECOPACK® series. Its forward voltage is 820 mV maximum at the full 3 A rated current — this sets the conduction loss per cycle in a continuous-current DC-DC converter or OR-ing diode application.
175 °C junction — thermal headroom for tight enclosures
Rated junction temperature spans -40 °C to 175 °C. That 175 °C ceiling gives the designer margin when the diode sits in a confined space with limited airflow — think industrial power supplies or automotive modules where ambient air inside the housing can reach 85–105 °C. The 4 µA reverse leakage at 170 V is specified at 25 °C; leakage climbs with junction temperature, so the thermal budget must account for the self-heating at full load.
SMBflat — low-profile surface-mount footprint
The SMBflat (DO-221AA) package is a leadless, flat-lead SMD variant. It sits lower than a standard SMB, which helps in board-edge clearance or when the PCB slides into a card guide. The surface-mount assembly is reflow-compatible; no through-hole staking step. The flat leads also reduce the parasitic inductance loop compared to a gull-wing SMC, a secondary benefit for the switching node of a 100 kHz+ converter.
Active production, ROHS3 — no LTB risk
Lifecycle status is Active. ROHS3 compliant. The ECOPACK® designation means the device meets ST's lead-free and halogen-free material declaration.