1500 W peak pulse — what the clamp means on your rail
The 1.5KE51: The reverse standoff voltage is 43.6 V — the rail it protects should sit at or below that level. Breakdown starts at 45.95 V minimum, and the clamp voltage at peak pulse current is 73.61 V max, so a 48 V bus sees the TVS clamp well before the downstream silicon's abs-max rating. Peak pulse current is 21.7 A under the same 10/1000 µs condition. The junction operates from -55 °C to 175 °C, which covers industrial and most automotive under-hood environments.
DO-201 axial — rework-friendly package
Through-hole DO-201AA (also called DO-27) axial package. The leads are easy to solder into a plated through-hole board and take hot-air rework without lifting pads — a practical choice for repair benches and low-volume builds.