STMicroelectronics lists the STPS30170CT as obsolete. Buyers should qualify any surplus lot for date-code consistency and original packaging — sealed factory reels with uniform date-codes are preferred over mixed-date auction lots that may be repackaged returns.
The 170 V reverse voltage rating provides headroom on a 48 V or 100 V bus, but it is not a 200 V part — a 48 V supply with 20 % transient margin stays safe; a 120 V bus would exceed the rating. The 15 A per-diode average current (total 30 A from the common-cathode pair) is the continuous rating; peak repetitive currents should be checked against the datasheet's surge curves. The 920 mV forward drop at 15 A is typical for a 170 V Schottky — higher than a 45 V Schottky's drop but necessary for the voltage class. The 20 µA reverse leakage at 170 V is moderate; expect it to rise with junction temperature, so thermal design should account for leakage-induced self-heating at high line and elevated ambient.