600 W peak pulse, 70 V standoff — what the ratings mean on the bench
The SMBJ70A-13-F: That 600 W figure is the non-repetitive surge rating — it tells you the device can absorb a single transient of that energy without failing, but it is not a continuous dissipation spec. The reverse standoff voltage is 70 V, meaning the TVS draws negligible leakage below that rail. Clamping starts at 77.8 V minimum breakdown and hard-clamps at 113 V maximum when the peak pulse current hits 5.3 A. For a 48 V or 60 V DC bus, the 70 V standoff gives headroom above the nominal rail while the 113 V clamp stays below typical downstream component breakdown thresholds.
Package and board-fit — DO-214AA SMB
The SMB body is larger than the SMA sibling, which translates to better thermal transfer to the PCB copper during the pulse — the junction-to-ambient thermal path is dominated by the pad area under the cathode tab.
Active production — no lifecycle concern
The base product number is SMBJ70, with the -13-F suffix denoting the reel packaging variant from Diodes.