Why the automotive suffix matters for under-hood designs
The 1N6267AHE3_A/D: The -55°C to 175°C junction temperature range is the giveaway — this is not a commercial-grade TVS sitting on a bench. The AEC-Q101 qualifier means it has passed the automotive stress suite (temperature cycling, humidity bias, power temperature cycling) and the lot traceability and datasheet limits are locked to the automotive screening burn-in screen. If the end-equipment lives anywhere near the engine bay or a thermal hotspot, this is the rating that tells you the junction has headroom at 125°C ambient.
DO-201AA axial package and through-hole assembly
Through-hole DO-201AA (DO-27) is the workhorse package for through-hole TVS clamps on legacy boards and industrial panels — it clips into a 5.08 mm lead spacing hole pattern without any SMT reflow profile. Tape & Box packaging is the standard variant for automatic insertion on legacy production lines. If your board is SMT-only, the 1N6267AHE3_A/D is not the right fit regardless of the electrical ratings.