1500 W peak pulse in a DO-214AB footprint
The 1.5SMC10A-M3/57T: The 103 A peak pulse current rating (10/1000 µs) tells you the device can absorb a substantial surge without failing short — the clamping voltage times the current gives the power rating, and the junction temperature stays within the -65°C to 150°C operating range.
Active lifecycle — no LTB clock ticking
Vishay lists this part as Active.
What the clamping voltage means for the rail
With a 14.5 V clamp at 103 A, this TVS protects an 8.55 V rail (the reverse standoff) from transients that would otherwise punch through downstream silicon. The 9.5 V minimum breakdown ensures the device starts conducting before the protected circuitry sees damaging voltage.