20 A per leg, 150 V blocking — the output-stage workhorse
The STPS40150CT is a dual-Schottky rectifier from STMicroelectronics, packing two 20 A diodes in a common-cathode TO-220 package. The common-cathode pair lets one TO-220 replace two discrete Schottkies, saving board area and reducing the pick-and-place count by one. The through-hole TO-220 suits point-of-load stages where thermal vias and copper pour carry the junction heat to a heatsink or chassis.
Forward drop and reverse leakage — the thermal budget drivers
At 20 A forward current the maximum forward voltage is 920 mV. The 8 µA reverse leakage at 150 V rated voltage is low enough to keep stand-by dissipation negligible, but leakage rises exponentially with junction temperature — the 175°C absolute maximum junction rating means the heatsink design must keep Tj well below that ceiling under peak load.