1500 W axial TVS for 12 V / 15 V rails
The 1.5KE20A-T from Diodes Incorporated is a 1500 W unidirectional Zener TVS diode in the through-hole DO-201AA axial package. It is designed to clamp transients on DC power rails with a nominal operating voltage up to 17.1 V — that is the reverse standoff voltage, the highest steady-state voltage the part lets pass without conducting. When a surge hits, the breakdown triggers at a minimum of 19 V and the clamping voltage holds at 27.7 V while shunting 54 A of peak pulse current (10/1000 µs waveform). That 54 A rating is the current the part can sink during the surge event without failing — it is not a continuous rating.
Where it fits on the board
The DO-201AA axial body is a standard through-hole footprint — two leads, one banded cathode. It reworks cleanly under a hot-air station or soldering iron because the leads wick heat away from the junction; the junction itself is buried in the epoxy body, not on a pad that can lift. The part is not rated for power-line protection (the spec flags Power Line Protection as No) — it belongs on a DC bus, not an AC mains input.
Sourcing an obsolete part
Diodes Incorporated lists the 1.5KE20A-T as Obsolete. The part is sourced to order against a BOM line; current pricing and lead time are quoted at the time of request.