The SM30T23AY is a 3000W (3kW) automotive-grade Zener TVS diode from STMicroelectronics, designed to clamp transients on 20V rails. Its single unidirectional channel handles a peak pulse current of 92.6A under the standard 10/1000µs waveform, clamping at 32.4V maximum. This is the part you spec for load-dump or ISO 7637-2 pulse protection in vehicle electronics — the 3kW rating gives enough headroom to absorb a 24V truck jump-start without letting the downstream rail see more than 32.4V.
AEC-Q101 and the full temperature range
AEC-Q101 qualification is the gating factor for any automotive Tier-1 or under-hood placement. For a 24V truck ECU or a 12V passenger-car ABS module, this part stays within its SOA across the full ambient range without derating the pulse power.
Package and mounting reality
The SMC body handles the 3kW pulse without cracking the epoxy — but the PCB copper area under the pad matters. For the full 92.6A peak, the datasheet recommends a minimum pad size of about 80 mm² copper on each side of the board to keep the junction temperature rise within limits.