125V clamping — the load's surge ceiling
The 1.5SMC91AHM3/H is a unidirectional Zener-type TVS diode in the DO-214AB (SMC) package, qualified AEC-Q101 for automotive and listed for telecom applications.
Peak-pulse and temperature envelope
The 1500 W peak pulse rating defines the energy the device can absorb during a single 10/1000 µs surge without degradation. The 12 A peak pulse current corresponds to that same waveform — above this current the clamp rises toward 125 V, so the downstream protection bandwidth and holding current budget are set together. Junction temperature range is -65 to 150 °C: the high end maps to full under-hood operating ambient after derating, and the low end covers cold-soak and cold-crank conditions in automotive deployments.
Automotive qualification and deployment
AEC-Q101 is not a marketing claim — it is a defined stress-test sequence (ESD, humidity, temperature cycling, terminal strength) run at the component level before the part enters automotive assembly flows. The 77.8 V reverse standoff is the working voltage in normal operation; transients above that level trigger the clamp. The single unidirectional channel means it protects one polarity — for AC lines or bidirectional clamping a dual-polarity part is required.
Sourcing the 1.5SMC91AHM3/H
Listed Active by Vishay General Semiconductor. The base product number 1.5SMC91 identifies the series family — any pin-compatible alternative within that series shares the same SMC footprint and standoff/clamp ratings at the same voltage grade.