What the 1500W rating means on the bench
The 1.5KE20A-G: That 1500W figure is the peak power the device can absorb in a single transient — not continuous — so it handles a surge like an inductive load dump or lightning-induced spike without self-destructing.
Clamping voltage and breakdown — what actually protects the rail
Reverse standoff voltage is 17.1V typ, meaning the diode stays off below that rail voltage. Breakdown starts at 19V min, and the clamping voltage at peak pulse current (54.15A) is 27.7V max. For a 12V or 15V supply rail, this clamps transients well below the typical 30-40V abs-max of downstream ICs — the margin is tight but workable.
Package and mounting — through-hole axial, no surprises
Housed in a DO-201AA / DO-27 axial package (supplier device package DO-201), the 1.5KE20A-G is a through-hole part. The axial leads let it sit upright on the board or lay flat — common in point-to-point wiring and breadboard prototyping. No power line protection built in, so it's strictly for signal or low-side DC rail clamping.