1500 W peak pulse — what the rating covers
The 1.5KE20AHB0G: The 17.1 V reverse standoff voltage means the diode does not conduct at normal battery voltage; clamping starts at 19 V minimum breakdown and hard-limits to 27.7 V maximum at the 56 A peak pulse current.
AEC-Q101 — the automotive qualification baseline
AEC-Q101 qualification covers the discrete semiconductor stress tests: temperature cycling, high-temperature reverse bias, and ESD robustness per the automotive electronics council standard.
Through-hole DO-201 — board-fit note
DO-201AA (DO-27) axial-lead package, 0.052-inch diameter leads — the hole size on the PCB should be 0.040 to 0.045 inch for a press-fit solder joint; the body length is about 0.375 inch, so adjacent components need clearance for the glass-passivated body. Single unidirectional channel — cathode band marks the polarity; reverse insertion defeats the clamping function, so the silkscreen orientation must match the protected rail.