Active automotive TVS with 1500 W peak pulse rating
The SMCJ18AQ-13-F: It is qualified to AEC-Q101, the automotive discrete semiconductor reliability standard, covering temperature cycling, ESD sensitivity, and production part approval process (PPAP) requirements.
Clamping window and pulse current handling
The minimum breakdown voltage is 20 V, meaning the device starts conducting (avalanche) at this threshold and clamps the transient to 29.2 V maximum. The 51.4 A peak pulse current rating at the standard 10/1000 µs waveform defines the surge capacity — for shorter pulses (8/20 µs) the peak current capability is higher, but the datasheet's derating curve must be followed. The 1500 W rating is derated linearly above 25°C ambient — at 125°C the peak pulse power drops to approximately 750 W, which still handles most automotive transients defined in ISO 7637-2 and ISO 16750-2.
DO-214AB SMC package and board integration
Housed in the DO-214AB (SMC) surface-mount package, the SMCJ18AQ-13-F has a compact footprint suitable for automated assembly. The SMC body measures roughly 7.1 mm x 6.2 mm with a 2.6 mm height — the copper pad area under the cathode tab sets the thermal resistance to ambient (RθJA). A 1 oz copper pour of at least 500 mm² on the PCB is recommended to keep junction temperature rise within limits during repetitive surges. The part is unidirectional (single channel), so polarity matters in the circuit — the cathode band must face the positive rail. It does not provide power line protection (no bidirectional clamping), so it is intended for DC signal and power lines where the transient polarity is known.