1500 W peak pulse, 22 V standoff — what the ratings mean for the board
The SMCJ22CA-13-F: The 22 V reverse standoff voltage means the device does not conduct below that rail — it sits across the supply line as a high-impedance shunt until a transient exceeds the threshold. For a 24 V bus, this clamp margin keeps downstream silicon within its abs-max rating during a surge event.
Package and temperature envelope
The SMC footprint provides a low-inductance path for the surge current and adequate copper area for heat sinking during the pulse. No power line protection feature is built in — this is a standard transient suppressor, not a crowbar or foldback device.