What 70.1 V standoff means for the protected rail
The 1.5SMC82A R7G: The reverse standoff voltage of 70.1 V is the DC working level the line can sit at without the TVS drawing significant leakage — the circuit runs normally when transients stay below this. Any overvoltage above the 77.9 V breakdown threshold forces the Zener channel into conduction and clamps the line at the specified maximum of 113 V.
A faster risetime event — 8/20 µs, common in lightning-induced surges — delivers more peak current into the same clamping voltage, and the clamping voltage itself rises as the di/dt increases. The listed 13.9 A Ipp at 10/1000 µs is the number to use when matching against a known surge waveform; derate toward the datasheet curve for faster events.
Sourcing posture — active production
The 1.5SMC82A is listed Active by Taiwan Semiconductor Corporation. Quoted to order through independent distribution against BOM quantities; lead time and lot traceability confirmed at RFQ.