AEC-Q101 TVS for 12V/24V automotive bus clamping
The 1.5SMC30CA-AU_R1_000A1: It clamps transients on 12V and 24V vehicle power rails — the 25.6V reverse standoff voltage sits above the nominal bus voltage, while the 28.5V minimum breakdown triggers before the downstream electronics see damaging overvoltage. That energy rating covers load-dump and inductive kickback pulses common in engine bays and body-control modules.
No power-line protection rating is listed — this is a signal or low-power rail protector, not a primary mains suppressor.