Clamping curve and standoff margin
The 1.5KE400AH: Reverse standoff voltage is 342V; the device begins conducting at 380V minimum breakdown and clamps the transient to 548V maximum at the 2.8A peak pulse current (10/1000µs waveform). The 38V gap between standoff and breakdown gives enough headroom for a nominal 342V bus to ride through normal ripple without the TVS conducting leakage, while still catching fast overvoltage events before the protected load sees 548V.
Package and procurement profile
DO-201AA axial — through-hole mount, mates into existing board layouts that use the 1.5KE family footprint.