1500 W peak pulse — the clamping ceiling for a 13.6 V rail
The 1.5SMC16A R7G: Its 22.5 V maximum clamping voltage at 70 A peak pulse current means a 13.6 V reverse standoff rail sees the transient clipped before it reaches the downstream IC's abs-max rating — the 15.2 V minimum breakdown voltage gives a guard band below the clamp point.
DO-214AB SMC — board footprint and thermal path
The SMC body's copper tab on the cathode side conducts the pulse energy into the PCB copper — the board's pad area and via count set the effective thermal resistance, not the package alone.
Active production — sourcing posture
Taiwan Semiconductor lists the 1.5SMC16A R7G as Active in production.