Transient suppression — what the 113 V clamping ceiling means
The 1.5SMC82A is a unidirectional Zener-based TVS diode rated 1.5 kW peak pulse power at 10/1000 µs surge waveform, packaged in the DO-214AB (SMC) footprint for surface-mount assembly. The standoff voltage of 70.1 V typ defines the working rail the protected circuit runs at without the TVS conducting; the 77.9 V minimum breakdown is where it begins clamping, and 113 V is the clamping voltage ceiling at the rated 13.5 A peak pulse current — that 42 V delta between standoff and clamping is the protection headroom a designer budgets against the expected transient amplitude.