408 V standoff, 658 V clamp — the rail protection envelope
The 1.5KE480A-E3/54: Its 408 V reverse standoff voltage keeps the protected rail below the avalanche threshold during normal operation, while the 658 V maximum clamp voltage at 2.28 A peak pulse current limits transients to a safe level. The breakdown voltage range starts at 456 V minimum, which means the diode begins conducting before the clamp voltage is reached — the avalanche region absorbs the surge energy before the downstream silicon sees overstress.
The 2.28 A peak pulse current at the clamp voltage shows the diode's ability to sink substantial surge current without failing short.
DO-201AA axial through-hole — mounting and board fit
Housed in a DO-201AA (DO-27) axial leaded package, the 1.5KE480A-/54 mounts through-hole on the PCB. The axial body allows point-to-point wiring or socketed insertion in high-reliability designs where surface-mount reflow might stress the junction.
Active production — sourcing posture
Vishay lists the 1.5KE480A-/54 as Active.