Transient protection for 12 V automotive and telecom rails
The 1.5SMC13AHM3/H is a Zener-type TVS diode from Vishay's 1.5SMC series, qualified to AEC-Q101 for automotive use. It clamps transients on a nominal 12 V supply — the 11.1 V reverse standoff voltage sits below the rail's maximum steady-state, so it stays out of conduction during normal operation and only fires when a surge exceeds the 12.4 V minimum breakdown threshold. That 18.2 V clamp is well within the typical 36 V absolute-max rating of downstream 12 V-rated ICs, giving a solid protection margin for load-dump and inductive kickback events.
Package and board-fit for DO-214AB
Housed in a DO-214AB (SMC) surface-mount package, the part's copper tab on the cathode side conducts heat into the PCB pad. The junction temperature range spans -65°C to +150°C, covering under-hood and telecom cabinet ambient extremes. No power-line protection — this is a unidirectional Zener, so it only clamps positive transients relative to ground; a bidirectional part would be needed for AC-coupled lines.
Sourcing and compliance for the BOM line
No pin-compatible alternative is recorded in this family — the 1.5SMC13 base number is the only unidirectional 11.1 V variant in the DO-214AB package.