Clamping performance and standoff rating
The 5.0SMDJ85A-AT/13: The reverse standoff of 85 V defines the continuous working voltage the circuit can hold without conduction — the TVS stays silent during normal operation. That 137 V clamping ceiling is the stress applied to whatever downstream semiconductor sits behind it — a 100 V MOSFET gate or a 100 V input pin sees 37 V of headroom above its rating, which is why the clamping ratio (137 V ÷ 94.4 V ≈ 1.45×) and the response time of a unidirectional Zener TVS are the first numbers an automotive harness or ECU designer checks against the IEC 61000-4-2 and ISO 7637-2 threat levels in the target system.
Automotive grade and thermal margin
AEC-Q101 qualification means the die and package passed the temperature cycling, humidity bias, and surge lifetime tests required for engine-compartment and body-control module deployment.
Package and production packaging
The DO-214AB (SMC) is the industry-standard footprint for 5 kW TVS diodes — the cathode tab thermal path through the board pad is the primary heatsinking mechanism, so the land pattern pad size and solder joint voiding matter more than the housing volume for sustained peak-pulse performance.