The 1.5SMCJ10C: The 1500W peak pulse rating at 10/1000µs is the primary selection axis for this class of transient voltage suppressor — it tells you the maximum energy the device can absorb during a single surge event without failing. At 79.8A peak pulse current, the diode clamps the overvoltage at 18.8V maximum, which is the ceiling the downstream circuit sees during a surge. For a 10V rail, an 18.8V clamp leaves enough headroom for most 12V and some 15V logic rails without the protected side seeing damage.
Standoff, breakdown, and clamping — the three numbers that decide protection fit
The reverse standoff voltage of 10V is the working voltage the TVS sees in normal operation — it sits idle below this level. The minimum breakdown of 11.1V is where conduction begins. The clamping voltage of 18.8V at the rated 79.8A peak pulse current is the figure you use to verify the protected IC's absolute-maximum rating has enough margin. If the downstream device datasheet specifies a 20V abs-max, this part clips just below it at 18.8V — a tight, workable fit.