The 1.5SMC27A: The footprint demands a copper pad area under the cathode tab to manage thermal dissipation during a 1500W peak pulse — the junction-to-ambient thermal resistance depends on the PCB copper pour, not just the package itself. Mounting is standard reflow; the tape-and-reel packaging (Cut Tape also available) suits pick-and-place for production runs.
For a 24V DC bus, the 23.1V standoff provides margin against nominal rail variations while still triggering before the downstream silicon sees damaging overvoltage.
The 1.5SMC series is a standard Zener TVS family with broad second-source coverage, so single-source risk is low.