What the 11.3V clamping ceiling actually means for the rail
The 1.5SMC7.5A M6G: The reverse standoff voltage of 6.4V is the working rail the diode ignores during normal operation — pick a standoff above your worst-case DC rail and the part sits dormant until the event.
1500W peak pulse rating means this part survives a single 10/1000 µs waveform — a 1 ms duration surge, not a sustained fault. If the load dump runs longer, the part thermally limits and the clamping voltage climbs. Breakdown is 7.13V minimum; the diode does not turn on until the transient pushes the rail past that threshold. Between 6.4V standoff and 7.13V breakdown the part is invisible to the circuit.
DO-214AB SMC footprint and thermal headroom
DO-214AB SMC package is the industry-standard TVS footprint — multiple manufacturers make this pinout, so a board laid out around the 1.5SMC7.5A M6G has genuine second-source options. Junction temperature rating runs to 150°C, so the part tolerates the hottest spots in an automotive or industrial enclosure without derating — the -55°C cold start capability covers equipment that has to boot in unheated environments.