Clamping parametrics and the automotive qualification
The 1.5SMC27CAHM3/I: Breakdown voltage min is 25.7 V, so a 24 V nominal automotive bus — which can transient to 36 V during load dump — gets clamped before the downstream 40 V-rated DC-DC converter sees an overvoltage. AEC-Q101 qualification means the part has passed the full automotive discrete stress suite: high-temperature reverse bias, temperature cycling, and ESD robustness — it belongs in an engine-control or transmission ECU that sees -40°C cold cranks and 150°C under-hood soak.
Package and board-fit for the DO-214AB footprint
Housed in a DO-214AB (SMC) case, the part is surface-mount with a standard JEDEC footprint that shares pad geometry with the smaller SMB and larger SMCJ series — a single PCB land pattern can serve multiple TVS current ratings if you need to swap during qualification.