What the clamping specs mean for your circuit
The 1.5SMC82AT3G: The 113 V maximum clamping voltage at 13.3 A peak pulse (10/1000 µs waveform) is the suppression ceiling — the TVS clamps any transients above that level and diverts the energy to ground, protecting downstream circuitry from overstress. The 70.1 V reverse standoff is the working voltage the diode sustains without conduction, so the protected rail should sit below that level in normal operation. At 1500 W peak pulse the 1.5SMC series handles short-duration surges common in supply and data-line environments — the 10/1000 µs rating is the standard 1.5 kW lightning-surge pulse per IEC 61000-4-5, not a continuous dissipation figure.
Sourcing the obsolete part
Independent surplus and excess-inventory channels are the sourcing path; lot traceability and genuine-part verification are the primary vetting steps for a TVS in this power class. A BOM line running this part should flag it for a cross-reference review before the board reworks or a new build is committed.