Still in active production — no EOL watch needed
The 1.5SMC30H: For a BOM that already qualifies this part, there is no urgency to find a drop-in replacement or stockpile.
This is a Zener-type TVS diode — one unidirectional channel, rated 1500W peak pulse power (1.5kW) for a 10/1000µs waveform. Breakdown starts at 27V minimum, and clamping is held to 43.5V at the full 36A peak pulse current. That clamp voltage is what the downstream silicon sees during a surge — a 5V-tolerant IC on a 24V bus would need secondary protection, but for 24V-rated relays, solenoids, or automotive loads the 43.5V ceiling is within the usual margin.
Automotive grade and temperature range
AEC-Q101 qualification means this part passed the automotive stress tests: high-temperature reverse bias, temperature cycling, and ESD robustness per the AEC discrete standard. Telecom is also listed as an application, so it is not locked to automotive-only BOMs.
Package and rework reality
The body is large enough to hand-place with tweezers and reflow with hot air if the board is already populated. Polarity is marked by a cathode band on the body; the unidirectional channel means orientation matters. No power-line protection feature (it is a unidirectional TVS, not a steering diode array), so it clamps one rail to ground.