1500 W bidirectional TVS for automotive transient protection
The SM15T15CAY: Bidirectional Zener TVS diode, 1500 W peak pulse power, AEC-Q101 qualified for automotive.
What the 1500 W rating means for your rail protection
The 1500 W peak pulse power rating (10/1000 µs) defines the energy the TVS can absorb in a single surge event without failing. For a 12.8 V standoff part, that translates to roughly 55 A peak pulse current on the longer waveform — enough to handle load-dump transients from an alternator or inductive kick from a relay coil. The 27.2 V clamp voltage is the ceiling the downstream circuitry must survive; a 12 V ECU rail with 30 V-rated input capacitors has comfortable margin. The 368 A rating on the 8/20 µs waveform is the more relevant spec for lightning surge or ESD events — it confirms the die can handle a very high current for a short duration without melting the junction.
AEC-Q101 and the 150°C junction — automotive deployment context
AEC-Q101 qualification passes stress tests required by Tier-1 automotive suppliers. 150°C maximum junction temperature allows placement near hot engine blocks without derating.
For a production BOM, this removes the obsolescence risk that often plagues older TVS families.