DO-214AB SMC package — reflow and board-fit
The 1.5SMC27AHE3/9AT comes in the DO-214AB (SMC) surface-mount package, also known as the SMCJ footprint. It is supplied on Tape & Reel, so it feeds straight into a standard pick-and-place line without a tray changeover. Check the MSL rating before the bake decision; a part this large in a molded package can trap moisture if stored beyond the floor-life label.
The reverse standoff voltage is 23.1 V — the rail it protects should never exceed that in normal operation. The 37.5 V clamp at 40 A means a 24 V automotive bus gets held below 38 V during a load-dump transient. That is within the abs-max of most downstream 40 V-rated DC-DC converters and linear regulators, so the TVS does the clamping without the converter having to survive the full surge.
AEC-Q101 automotive grade — the qualification story
The 1.5SMC27AHE3/9AT carries AEC-Q101 qualification, meaning it has passed the automotive-grade stress tests: high-temperature reverse bias, temperature cycling, and ESD robustness. The series is also branded TransZorb, Vishay's own TVS process that delivers the tight clamping ratio typical of the 1.5SMC family. For a new automotive ECU design or a BOM fill on an existing line, this part is a standard-shelf item that does not trigger a last-time-buy planning cycle.