The 1.5KE540A: The 460 V reverse standoff voltage is the maximum continuous DC voltage the part can block without conducting — it sits on a 460 V rail and stays invisible until a surge pushes the line above the 513 V minimum breakdown threshold. When that happens, the diode clamps the transient to 740 V maximum, shunting up to 2 A of peak pulse current (10/1000 µs waveform) away from the protected circuit. The 1500 W peak-pulse rating is the power the device can absorb in a single 10/1000 µs surge — enough for industrial power-supply transients, motor-drive reflections, or lightning-induced spikes on a 460 V bus.
Package, mounting, and board-fit reality
Housed in a DO-201AA axial-lead package, the 1.5KE540A is a through-hole part — the leads are soldered into plated through-holes on the PCB. The DO-201 footprint is standard for TVS diodes in this power class; the axial body allows the device to be mounted standing upright or laid flat, depending on the board clearance. The supplier device package is DO-201, which is the same mechanical outline as the industry-standard 1.5KE series. It is a unidirectional Zener TVS — one channel, polarity matters. The cathode band on the body must face the protected rail; the anode connects to ground. Reversing it turns the diode into a forward-biased rectifier and the protection disappears. Power line protection is not supported — this part is for DC signal or power rails, not AC mains.