The 1.5SMCJ200AS_R1_00001: The 200 V reverse standoff (typ) is the DC working voltage the line can sit at continuously without the TVS conducting — the protection window opens above this. 1.5 kW peak pulse rating in the 1.5SMC series is the surge-withstand ceiling for a single-event spike; the clamping voltage at that current confirms the Zener knee has fully engaged and the device is absorbing energy in the breakdown region.
Temperature grade and mounting
DO-214AB (SMC) package with tin-lead finish, surface-mounted on the PCB — the solder mask opening and landing pattern are the standard SMC footprint, and the central SMD tab carries the thermal path to the board plane.
What this part is and where it sits in the family
Panjit lists this as a Zener-type unidirectional TVS — the Zener characteristic gives a sharper knee than a conventional avalanche diode, which matters for precision clamping on sensitive rails. Power line protection is marked No — this is a board-level protection device, not a mains-entry clamp, so it handles the local rail transient after the input stage has already done its sorting.