1500W peak pulse, 14.5V standoff — the protection threshold
The 1.5KE18CHE3/54: Its 14.5V reverse standoff voltage means the part does not conduct at normal 12V system levels; clamping starts at 16.2V minimum breakdown and limits transients to 26.5V maximum at 56.6A peak pulse current.
Obsolete — sourcing through independent channels
Vishay has marked the 1.5KE18CHE3/54 as obsolete. For a BOM that requires this exact order code, the sourcing path is a last-time-buy or spot-market procurement.
Through-hole DO-201AA (DO-27) axial package — the leads are formed for through-hole insertion on a standard 0.4-inch lead spacing. The 1.5KE package suffix indicates the same body size as the rest of the 1.5KE series, so existing PCB footprints for a 1.5KE18 TVS accept this part without layout change. The wide junction temperature margin means derating for high ambient is minimal at the 1500W peak pulse rating.