The SMBJ85E3/TR13: Microchip lists the SMBJ85E3/TR3 as Active, so there is no last-time-buy clock ticking. The DO-214AA SMB package is a common footprint, and the part ships on Tape & Reel — standard for pick-and-place assembly.
The reverse standoff voltage is 85V — this is the maximum DC voltage the TVS will sit across without conducting leakage. The breakdown voltage is guaranteed at 94.4V minimum, so on an 85V rail the part stays off under normal conditions and only starts clamping when the rail rises above that threshold. When a surge hits, the clamping voltage peaks at 151V at the rated peak pulse current of 3.9A under the 10/1000µs waveform. That 151V ceiling is what the downstream components see — make sure your DC-DC converter or load switch can survive that transient without secondary failure. For an 85V rail, this is a secondary protection tier — it handles moderate transients from inductive load switching or coupling, not direct lightning strikes.
Temperature range and rework considerations
The DO-214AA SMB package has a single cathode tab on the bottom; rework with hot air is straightforward, but watch the pad thermal mass — preheat the board to 100-120°C before lifting the part to avoid pad damage. The part is unidirectional — a single Zener junction. Orientation matters: reverse the part and it behaves like a forward-biased diode, not a clamp.
Sourcing and ordering for this TVS
The SMBJ85E3/TR13 is a standard catalog item from Microchip.