TVS diode — peak pulse power and clamping performance
The 1.5SMCJ30A_R1_00001: The 1500W peak pulse rating at 10/1000µs defines what this part survives on a supply rail — a single-surge event of that waveform shape dumps energy into the clamp, and the TVS conducts it to ground before the downstream circuit sees overstress. That 31A peak pulse current is the clamping headroom at the rated surge shape; the part holds the clamp voltage at 48.4V maximum while conducting that current, which means the protected rail sees a hard ceiling rather than an uncontrolled spike. The reverse standoff of 30V sets the continuous working voltage the TVS ignores in normal operation. When the transient exceeds 33.3V (the breakdown threshold), the device turns on and clamps. The 48.4V ceiling at peak surge current is what the downstream IC or regulator sees during the event — tight enough to protect a 24V rail with margin, wide enough to survive the 1.5kW event without going into thermal runaway. Unidirectional polarity means it protects one polarity only — positive transients on the supply rail are clamped, negative events pass through or are not blocked. If the board needs bidirectional protection, the 1.5SMCJ series carries both polarities; confirm the suffix before specifying the polarity variant for the BOM line.