AEC-Q101 qualification — the audit-ready gate
The 1.5KE400H carries AEC-Q101 qualification, meaning the part has passed the full automotive discrete semiconductor stress battery: temperature cycling, high-temperature reverse bias, and humidity testing with documented PPAP-level traceability. An OEM auditor reviewing the BOM line for a 324 V nominal bus transient suppressor sees the AEC-Q101 certificate as the hard stop — no industrial-grade 'automotive-capable' substitute clears that gate.
1500W surge window — breakdown, clamp, and standoff
The reverse standoff voltage of 324 V means the TVS remains transparent below that bus level — leakage stays within datasheet limits — while the minimum breakdown of 360 V ensures the avalanche trigger is well above the nominal rail. The 574 V clamp must sit below the downstream load's absolute maximum rating; a 600 V-rated MOSFET or IGBT has only 26 V of margin at the clamp ceiling, so the surge energy must be verified against the load's avalanche capability.