Clamp voltage and peak pulse current
The 1.5SMC68A: For a 48V rail, a 1.5x clamping margin (72V) is comfortable; for a 60V rail the 92V ceiling is tighter, and the downstream component's transient-withstand rating must be confirmed against that figure before committing to the BOM line.,.
Junction temperature and derating
Rated junction temperature runs to 150°C with an operating range starting at -55°C, making this viable for equipment that sees cold soak before power-up as well as thermally stressed enclosures. The 1.5 kW rating is a peak-pulse figure — continuous dissipation is far lower and is set by the board-level thermal design, not by this surge rating.,.