Clamping voltage and breakdown margin
The 1.5SMC180CA-E3/9AT: The reverse standoff voltage is 154 V — the rail the part protects should never exceed this in normal operation. That 75 V window between the rail and the clamp gives headroom for the TVS to remain off during steady-state ripple while still catching fast transients. Operating temperature spans -65°C to 150°C junction, so the part survives cold-soak and hot reflow profiles without derating the pulse power at the extremes.
DO-214AB surface-mount footprint
Housed in a DO-214AB (SMC) package, the same footprint as the SMCJ series. The large copper tab on the bottom side conducts heat into the PCB pad — the board copper area directly sets the thermal impedance for repetitive pulse trains.