This is my fourth or fifth unsucsessful attempt for last half-year to calibrate AOUT_LC module.
Yesterday i’ve replaced R49/51 with 100k ones and get perfect calibration for 1V, 2V and 4V values. But i have 11,22 instead of 8V. Or 0/11,22/11,22 with Min/Mid/Max
Replaced opamps, shift registers, checked all resistors and here what i have.
(1 - Vdd 4,95v)
I was confused by one point - why there’s non linear value of 4,32v at 8V calibration setting. Is it R-2R related? I measured resistance between shift register outs and opamp inputs. Is it looks acceptably?
Shift register? I replaced it three times with different suppliers ones.
Or maybe it’s software related?
I’m totally confused and need your help.
PS. Bipolar supply values is +11,87/-11,97