Transient protection for 185V DC rails
The 1.5SMC220A is a 1500W Zener TVS diode from the Littelfuse 1.5SMC series, designed to clamp voltage transients on DC power rails up to 185V. It is a single unidirectional channel, so it clamps only one polarity — use it on positive DC rails with the cathode to the protected line.
The DO-214AB footprint is shared by many TVS diodes in the 1500W class, making board-level replacement straightforward if a different voltage rating is needed later.
The part is classified for General Purpose applications, which covers industrial, telecom, and consumer equipment. RoHS compliance is standard for the series, though the exact certification status should be confirmed against the manufacturer's documentation at order time.