600W peak pulse power, 85V standoff — the protection threshold for a 60-85V rail
The SMBJ85A-13: The 85V reverse standoff voltage (VRWM) is the maximum continuous DC voltage the diode will not conduct on — a 60V or 72V bus with margin to 85V is the intended operating envelope. The breakdown voltage floor of 94.4V is where conduction starts, and the 137V clamp is the hard ceiling the load sees during a surge.
DO-214AA (SMB) surface-mount — board-fit and thermal path
The junction operates from -55°C to 150°C, so the board's copper area and via count under the pad must sink the 600W pulse's heat without exceeding the solder joint's temperature limit. Supplied on Tape & Reel (TR) or Cut Tape (CT), the part is compatible with standard pick-and-place assembly. The SMB footprint is shared across the SMBJ family, so a single PCB land pattern serves the full voltage range from 5V to 188V standoff.