Dual Schottky in a TO-220-3 — what the ratings tell you
The STPS40M100CT is a dual Schottky rectifier from STMicroelectronics, housing two 20 A diodes in a common-cathode configuration inside a single TO-220-3 through-hole package. Each diode is rated for 100 V reverse voltage and delivers a forward voltage drop of 780 mV at the full 20 A forward current. The fast-recovery characteristic — ≤ 500 ns at > 200 mA — means this part is tuned for switching supplies and output rectification where reverse-recovery losses matter, not just conduction drop. The junction temperature maxes at 150 °C, which sets the heatsink requirement for continuous 20 A per leg.
The base product number STPS40 covers a range of voltage and current variants in the same TO-220-3 footprint, so if a future design needs a different Vr or If rating, the pin-compatible sibling is a direct swap without a board spin.