Protection window and what the ratings mean
The 1.5SMC9.1CAHE3/57T: The standoff voltage of 7.78 V sets the working rail the protected node sees in normal operation — the TVS stays off and leaks minimally until the transient pushes the line above this level. The breakdown threshold of 8.65 V minimum is where the device begins to conduct, which is where the clamping action starts. This 7.78 V standoff / 13.4 V clamping window targets 12 V automotive rails where load-dump transients can spike well above the supply rail — the TVS clamps the overvoltage before the protected ECU input sees it.
AEC-Q101 grade and automotive deployment
Junction temperature rating is -65 to 150 °C, which covers the under-hood ambient band with margin — an ECU in a sealed engine bay that hits 125 °C still has 25 °C of Tj headroom before the TVS derates.
DO-214AB package and board assembly
Tape & Reel packaging is the default for high-volume assembly; the part mates with standard SMT pick-and-place tooling at the DO-214AB package height.