What AEC-Q101 means for this Zener selection
The 1.5SMC6.8AHM3/H carries AEC-Q101 qualification — this is not a marketing claim but a passed stress-grade test suite covering temperature cycling, humidity, and surge life, accepted by OEM safety and reliability teams under IATF 16949 programs. Reverse standoff sits at 5.8 V typical, with a 6.45 V minimum breakdown — the part sits passively above the rail in normal operation and clamps when the transient pushes the line above that band.
1500 W peak pulse and the 143 A figure
At 143 A peak pulse (10/1000 µs), the clamping voltage of 10.5 V is the figure the downstream IC sees — the 1.5SMC family sizes the junction to absorb the transient energy without degradation, and the DO-214AB SMC die attach thermal path is what keeps the unclamped portion from migrating into the board copper. Operating junction temperature is rated to 150 °C — the -65 °C lower bound tells you the part survives cold-transit and high-altitude board bring-up without the leakage floor degrading the reverse characteristic. Unidirectional single-channel — the polarity of the transient matters on the line; bidirectional protection requires a dual-diode or a separate polarity-flipped part, which the 1.5SMC family does not provide in this unidirectional variant.