15V standoff and the clamping story
The 1.5SMCJ15A_R1_00001: The 15V reverse standoff is the working voltage — above it the Zener channel begins to conduct and the diode is in clamp mode. The 1.5 kW peak pulse rating is sized for that single-event transient energy; it is not a continuous dissipation figure. The DO-214AB (SMC) package requires a well-defined cathode-tab pad on the PCB; thermal relief under the tab and adequate copper area determine whether the part self-heats within its rated TJ margin during clamping events.
General-purpose TVS — not a power-line protector
The series designation carries a general-purpose application note and explicitly flags power-line protection as no — meaning this part is selected for board-level transient suppression on individual signal or power rails, not for AC mains clamping where a dedicated surge protective device (SPD) would be specified instead. The unidirectional channel clamps positive transients; it does not address bidirectional or AC-coupled polarity reversals.