1500 W peak pulse — what the rating means for your rail
The 1.5SMC22A-M3/57T: Breakdown occurs at a minimum of 20.9 V, and the clamping voltage is capped at 30.6 V. For a 12 V or 15 V rail, that standoff gives margin; for a 24 V rail the 18.8 V standoff is too low and the device would conduct at the operating voltage. The device is rated for general-purpose circuit protection and is not intended for power-line protection (no internal power-line protection circuitry).
DO-214AB SMC package — board-fit and footprint
The package is a standard JEDEC outline for TVS diodes in this power class — the 1500 W rating demands the larger SMC body for thermal dissipation, not the smaller SMA or SMB packages used for lower-power parts. The part is supplied on Tape & Reel (TR) — the /57T suffix indicates the reel packaging variant. Mounting is surface-mount; the copper pad area under the cathode tab on the PCB sets the thermal impedance to ambient, so the recommended land pattern from the Vishay application note should be followed for full 1500 W capability at elevated temperatures.
The device is a single unidirectional channel — one TVS die in the package.