Schottky pair for 45 V rails
The STPS1545CT is a dual Schottky rectifier in a common-cathode configuration, rated for 45 V reverse voltage and 7.5 A average forward current per diode. The TO-220-3 through-hole package keeps the thermal path short — the exposed metal tab carries the cathode and sinks heat into the board or a clip-on heatsink. With a forward drop of 570 mV maximum at 7.5 A, the conduction loss per diode stays under 4.3 W at full load. That figure doubles in a common-cathode pair if both diodes conduct simultaneously, so the thermal design should budget for the sum.
Reverse leakage and temperature margin
Reverse leakage is specified at 100 µA maximum at 45 V. Leakage in Schottky diodes doubles roughly every 10 °C rise, so at 125 °C junction the leakage can exceed 1 mA — enough to shift the bias in a low-current sense circuit or add to the standby loss in a continuously powered rail. The junction temperature rating of 175 °C maximum gives headroom for high-ambient or poorly ventilated enclosures, but the leakage at that extreme should be derated in the BOM calculation.
