1500 W peak pulse — what the rating means for your protection budget
The 1.5KE20C-E3/54: At that pulse condition the clamping voltage holds at 29.1 V max while the diode handles 51.5 A of peak pulse current — a combination that shunts surge energy from a 16.2 V nominal rail before it reaches the downstream silicon.
Bidirectional clamping and the voltage window
The reverse standoff voltage is 16.2 V, meaning the diode draws negligible leakage current below that rail voltage in normal operation. Breakdown starts at 18 V minimum, and the clamping ceiling is 29.1 V at the rated pulse current — a 13 V window from standoff to clamp that limits the overvoltage exposure of a 12 V or 15 V bus.
Obsolete — sourcing reality for the BOM line
Vishay has marked the 1.5KE20C-/54 as obsolete.
Through-hole package and temperature range
The DO-201AA (DO-27) axial-lead package is a through-hole form factor that solders into a single-hole board layout — the lead bend and hole diameter follow standard axial diode footprints.