Active production – no end-of-life worry
The 1N6156AUS: For BOM planning, this removes the single-source risk that comes with a NRND or obsolete TVS diode.
The 29.7V reverse standoff means it stays out of the way on a 24V rail, but when a transient comes, it shunts the energy before the downstream silicon sees the overvoltage. On the repair bench, a scorched SQ-MELF package with a shorted junction tells you the surge exceeded the part's energy rating – check the upstream source before swapping.
SQ-MELF package – footprint and thermal path
Housed in a C, SQ-MELF surface-mount package, the 1N6156AUS sits on a solder pad that doubles as the thermal path.