The 1.5SMC8.2A-E3/9AT: The 1.5SMC8.2A clamps transients at 12.1 V maximum under a 124 A peak pulse (10/1000 µs waveform), which defines the voltage the protected rail sees during a surge event — the downstream IC never experiences more than 12.1 V regardless of the incoming overvoltage amplitude. The 7.02 V standoff (typ) sets the continuous working voltage below which the TVS stays off and leaks minimally; above it the device enters avalanche breakdown and clamps. Choosing a standoff above the rail's nominal VCC prevents idle-state leakage from creeping into the protected node.
Temperature grade and unidirectional polarity
Unidirectional polarity means it clamps positive transients only — bidirectional snubbing (ESD events that go negative on the signal line) requires the bidirectional variant in the same 1.5SMC family, not this part.
Lifecycle and sourcing posture
The 1.5SMC series is a long-run family; sourcing confirmation of the exact 8.2 V standoff variant should be requested at RFQ.