7.02 V standoff, 12.1 V clamp — what the numbers mean for the protection window
The 1.5SMC8.2A-M3/9AT: The reverse standoff of 7.02 V typ means the TVS stays invisible on the line during normal operation; it only turns on when the transient pushes the line above roughly 7.79 V minimum breakdown. At 1500 W peak pulse power rating, this part handles the standard 1.5 kW surge class — common in AC-line protection, bus-clamp, and motor-drive environments where lightning-induced transients or inductive kickback exceed what a downstream regulator can absorb. The 150 °C junction temperature ceiling gives thermal headroom in enclosed panels without active cooling.
Who is still building boards with the 1.5SMC8.2A series
The TransZorb® construction (Vishay's internal glass-junction passivation) gives it better surge-survival than a plain Zener clamp in repetitive transient environments.