Transient protection for 70 V DC rails
The minimum breakdown voltage is 77.8 V, which sits above the 70 V standoff — that gap ensures the diode stays off during normal rail ripple and only conducts when a real transient pushes the line above the breakdown threshold. The 113 V maximum clamp at 13.3 A is the ceiling; the load's absolute maximum rating should sit below that to survive a worst-case strike.
That means no last-time-buy scramble for the foreseeable future — procurement can commit the BOM line without a successor watch.
The base product number SMCJ70 covers the family; the suffix indicates the standard screening level.