The 1.5SMCJ100CA_R1_00001: The 1.5SMCJ series is a bidirectional TVS diode family — the CA suffix marks unidirectional polarity, and it clamps transient voltage spikes on signal or power rails that sit below its 100 V standoff rating. Rated 1500 W peak pulse (10/1000 µs waveform), which is the standard surge-withstand for mains-adjacent and industrial DC bus protection; a 9.3 A peak pulse current flows through the device when it clamps at 162 V, dissipating that surge energy before it reaches the downstream IC or connector it shields.
Clamping voltage and breakdown — the protection window
The minimum breakdown sits at 111 V; the device does not begin conducting until the transient pushes the rail above that threshold. At 162 V the clamping ceiling caps whatever the surge delivers — the downstream circuit sees 162 V at most, regardless of surge severity up to the 9.3 A peak. That 51 V window between breakdown and clamping is the let-ratio trade-off: tighter clamping costs more standoff headroom, and this part sits in the middle — suited for rails that tolerate brief excursions above 111 V but need hard clamping before 162 V.