The 1.5SMC43AHE3/57T is a Zener-type TVS diode from Vishay's 1.5SMC series, branded TransZorb®. It is qualified to AEC-Q101, the automotive discrete semiconductor reliability standard, making it suitable for ECU and under-hood transient protection where PPAP documentation is required. The reverse standoff voltage is 36.8 V, and breakdown occurs between 40.9 V minimum.
AEC-Q101 qualification and automotive fit
AEC-Q101 qualification means the part has passed stress tests including temperature cycling, high-temperature reverse bias, and ESD robustness per the automotive council's discrete semiconductor standard. This is the baseline for any Tier-1 ECU BOM that requires traceable reliability data. The 150°C maximum junction temperature aligns with under-hood ambient profiles where the TVS may see sustained heat soak. The -65°C low end covers cold-crank and arctic storage conditions without parametric shift. No power line protection is claimed — this is a unidirectional transient suppressor for signal or low-side DC rails, not for AC mains or hot-swap bus clamping.
The DO-214AB (SMC) footprint is a standard JEDEC outline for 1.5 kW TVS diodes. The copper pad area under the cathode tab sets the thermal resistance — a larger pad lowers RthJA and improves surge derating at elevated ambient temperatures. The reel quantity is not specified here but is standard for the SMC package size.
No official second-source or pin-compatible cross-reference is recorded in this listing.