The 1.5SMC24AHE3/9AT is a Zener-type transient voltage suppressor from Vishay's 1.5SMC series, part of the TransZorb family. It is qualified to AEC-Q101, the automotive-grade discrete semiconductor reliability standard, meaning it has passed the temperature cycling, high-temperature reverse bias, and ESD sensitivity tests required for under-hood and chassis-mounted electronics. The minimum breakdown voltage is 22.8 V, ensuring the TVS begins conducting before the protected rail exceeds the safe operating area of downstream components. No power line protection is provided — this is a unidirectional device intended for signal or low-voltage DC rail clamping.
This surface-mount footprint is common for 1500 W TVS diodes and mates with standard SMC solder pads. The Tape & Reel (TR) packaging suits automated pick-and-place assembly. For a BOM cost engineer, the AEC-Q101 grade adds traceability and reliability screening that is non-negotiable for automotive production but may be over-specified for non-automotive designs.