Standoff and breakdown — the TVS window
The 1.5SMC7.5AHR7G: The reverse standoff voltage sits at 6.4 V typical — below this the device leaks minimally and presents no load to the protected line. The breakdown threshold begins at 7.13 V minimum, so the 6.4 V standoff gives roughly 0.73 V of headroom before the TVS begins conducting.
AEC-Q101 and the automotive application context
AEC-Q101 qualification means the die and assembly have passed the automotive stress sequence — temperature cycling, high-temperature reverse bias, humidity cycling — giving the part a qualification pedigree that a standard commercial TVS lacks. This is the grade required for any ECU, BCM, or sensor module that sits in or adjacent to the engine bay or cabin environment.