I have two question about ADP8140.
Can ADP8140 operate under 3-string?
Under 1-string open circuit(SINKx),
Absolute Maximum Ratings about SINKx is 21V(max).
If all LED gets shorted when using 100V as power line we would see 100V on SINKx .
This condition of all LEDS short is valid when testing for system integrity and will exceed SINKxs Absolute maximum rating .