What 62V standoff and 85V clamping mean for the clamp
The 1.5SMC62A R7G: For a 48V industrial bus, that 85V clamp gives downstream ICs a fighting chance even with a fast surge.
1500W peak pulse — the design number that sets board-level layout
The DO-214AB package thermal impedance is the limiting factor — keeping the cathode pad copper area adequate and the thermal vias under the tab populated is what lets the junction stay below 150°C TJ during the event. The 18A peak pulse current rating tells you the clamping voltage is achievable at that current — if your actual surge source impedance is very low, the diode will conduct hard and the clamping voltage will be the governing number, not the standoff.
Junction thermal margin and the -55°C cold end
Rated to 150°C junction temperature with a bottom-end limit of -55°C — this covers the outdoor-equipment and transportation temperature band without derating. The upper limit is set by the silicon-gate Zener structure; exceeding it on a sustained basis shifts the breakdown voltage and eventually degrades the clamping characteristic.
Listed as Active by Taiwan Semiconductor Corporation. Quoted to order; availability and lead time confirmed at RFQ.