25 V, 10 A Schottky — conduction loss and thermal budget
The STPS10L25D is a 25 V, 10 A Schottky barrier rectifier from STMicroelectronics in a TO-220AC through-hole package. Its primary role is low-voltage, high-current rectification where forward voltage drop directly determines efficiency — power-supply output stages, OR-ing diodes in redundant supplies, and freewheeling diodes in DC-DC converters. The forward voltage is specified at 460 mV maximum at the full 10 A forward current. That 460 mV at 10 A means 4.6 W of conduction loss at rated load — the heatsink must pull that heat away to keep the junction below the 150°C maximum.
Reverse leakage and standby power
Reverse leakage is 800 µA at the rated 25 V reverse voltage. In a continuous-conduction application that leakage contributes to standby dissipation and rises with junction temperature — a Schottky's leakage doubles roughly every 10°C above 25°C, so the thermal design must account for the leakage component at the operating junction temperature.