The STPS20H100CG is a dual Schottky rectifier from STMicroelectronics, configured as a common-cathode pair in a D2PAK (TO-263) surface-mount package. The 100 V reverse voltage gives headroom for 48 V telecom rectifiers, 24 V industrial power supplies, and 12 V automotive alternator loads. Junction temperature is rated up to 175°C, which matters when the rectifier sits near a hot transformer or in a sealed enclosure.
770 mV forward drop at 10 A — thermal budget driver
At 10 A per diode the forward drop is 770 mV, so each diode dissipates about 7.7 W in conduction. The D2PAK's exposed tab carries most of that heat to the PCB copper plane. If you are running both diodes near full current, the total dissipation hits 15.4 W — that needs a solid thermal via pattern under the tab and at least 2 oz copper on the top layer. The 175°C junction rating gives some margin, but the tab temperature is what limits continuous output. Reverse leakage is 4.5 µA at 100 V, low enough that it does not add meaningful loss in offline supplies.
STMicroelectronics lists the STPS20H100CG as Active. That means no last-time-buy clock is running, and the part is still a standard production item through normal distribution. If you are stocking spares, the D2PAK reels store well — MSL 1 typically, so no bake required before reflow as long as the bag seal is intact.