78 V standoff, 126 V clamp — the protection envelope
The SMCJ78A-13: The 1500 W peak-pulse rating at 10/1000 µs means it can absorb a 1.5 kW surge for a millisecond — typical for lightning-induced transients or inductive load dumps in industrial and telecom power buses. The 78 V standoff voltage is the maximum DC or AC peak the TVS will not conduct at, so it sits across the rail without leakage until a transient exceeds the breakdown threshold.
DO-214AB SMC package and board integration
The operating temperature range spans -55 °C to 150 °C, covering the full industrial and automotive ambient envelope.