The 1.5SMC9.1CAHE3/9AT: At the clamping voltage of 13.4 V, the part clamps the spike before the downstream circuit sees it, and the 112 A peak pulse current at that clamping point confirms the absorption capacity the clamping stage must deliver. For a 12 V automotive rail, a 13.4 V clamp gives adequate headroom above the nominal supply while keeping let-through voltage below what most downstream ICs tolerate.
Voltage stack — standoff, breakdown, and clamping
The reverse standoff of 7.78 V defines the maximum voltage the protected node sits at during normal operation — below this the TVS leaks minimally and the protected rail sees no clamp action. Breakdown starts at 8.65 V minimum; once the transient pushes the node into this band the TVS begins conducting and redirects the surge energy.
Automotive qualification and thermal range
AEC-Q101 qualified, part of the TransZorb® series in the 1.5SMC automotive family. Junction temperature range is -65°C to 150°C, which covers the under-hood band — engine-bay ambient that peaks near 125°C in summer still leaves margin before the 150°C TJ ceiling. The qualification stress testing covers temperature cycling, humidity, and mechanical shock, so the DO-214AB package is field-replaceable on an automotive board without special handling concerns.
DO-214AB (SMC) package with the matching SMCJ supplier device designation — standard metal-electrode pad footprint on the cathode side. Surface-mount reflow profile; the cathode stripe marking is the orientation reference. For automotive boards requiring hand-rework, the SMCJ form factor is accessible with a fine-tip iron and drag-solder technique, though hot-air is cleaner. No exposed paddle; thermal relief on the pad lands manages solder fillet geometry during assembly.