Clamping and standoff — what the three voltage specs mean
The 1.5SMCJ26CA_R1_00001: The 26V reverse standoff is the maximum rating the protected rail runs at continuously without the TVS drawing significant leakage — above it the device begins to avalanche and clamp. With a 1.5 kW peak pulse rating, the part survives the surge energy without going into thermal runaway — the clamping voltage of 42.1V at 35.6A is the voltage the downstream load actually sees during the event.
Bidirectional protection on a single polarity rail
The CA suffix denotes a bidirectional polarity variant — the single channel protects against transients of either polarity on a rail referenced to a fixed ground, so you do not need two oppositely-polarised unidirectional parts to cover both polarities.
Operating temperature and package
TJ-rated to 150°C — the junction can reach full temperature in high-ambient or poorly-ventilated enclosures without derating, covering both under-hood automotive and industrial control cabinet environments.