The 1.5SMC27AHM3/I is a Zener-type TVS diode from Vishay's 1.5SMC series, part of the TransZorb® family. The reverse standoff voltage is 23.1V typical, with a breakdown voltage range starting at 25.7V minimum. This means the diode begins conducting at roughly 26V and holds the line below 38V during a surge — a tight clamp for 24V nominal rails in automotive or telecom gear.
Automotive qualification and deployment context
The single unidirectional channel and no power-line protection flag mean this diode is intended for signal or low-side protection, not for clamping the main battery bus. It suits 24V sensor inputs, CAN bus lines, or telecom line-card interfaces where a 23.1V working voltage leaves margin below the 25.7V breakdown threshold.
The SMC footprint is standard — the cathode band aligns with the marked end; the tab carries the cathode and sinks heat into the PCB copper pour. Tape and reel packaging suits automated pick-and-place. No special moisture sensitivity level is stated in the record, but the DO-214AB body is molded epoxy — standard MSL 1 handling applies unless a specific bake is called out on the reel label.