Chronic failure of #2 channel (pin#2 output).
1) I am using this device in 4 different systems. Current source Pin 1 and pin 2 are in identical circuits.
2) Each system uses the 100ua source channels to bias external temperature sensors.
3) I seem to have chronic failures for the pin#2 output channel only, on 2 of the systems, (different PCBs but identical circuits). The other 2 systems only use the pin#1 output. Never a failure.....no matter how much testing/handling!
4) As a test, I can short output channel#1(pin1) hi, lo, or let float, yet channel can not be made to fail. Very robust.
5) when a #2 channel fails, I replace chip, and after functioning for a short bit(maybe 10 minutes or so), if fails again.
FAILURE MODE = seems to source 6 ua or so. Very consistent failure mode. Channel 1(pin1 side) never fails.....
(Static controls in place, also, pin1 and pin2 are both exposed to same environments(obviously).
Any thoughts on this failure mode? See schematic attached.