Transient clamping at 113 V protects the 70 V rail
The 1.5SMCJ70A-AQ: At 70 V standoff, the protection threshold sits 7.8 V above the rail — a 113 V clamping ceiling gives the downstream automotive ECU 42 V of headroom during a load-dump or inductive kickback event before the protected node sees damaging levels. The single unidirectional channel clamps positive transients to ground; for bidirectional or AC rails a different polarity variant would be required.
DO-214AB SMC for automotive ECU board assembly
The SMC (DO-214AB) package is the automotive-standard footprint for TVS protection on ECU input rails — the flat-body geometry suits reflow profiling and the wide solder pad supports adequate thermal dissipation for a 1.5 kW device. Operating junction temperature extends to 150 °C, which covers engine-bay ambient excursions when the board thermal design keeps the case temperature below the derating curve. Marked for automotive applications per the -AQ suffix convention, though no AEC-Q grade is listed in the available specification data — the buyer should confirm qualification documentation against the specific OEM requirement before releasing to production.