We are use the AD7785 in a Oxygen measurement system. At this time we manufactured ca. 600 pieces. At the last 100 we have problems with the precision of the AD7785.
The problem is the value of the full scale register. The failed devices (ca. 75pc from 100) have all the Factory default value of exact hex 500000 at power on in this register.
We can set the full-scale register manually to an value that the full-scale voltage and the read out of the AD7785 is proper, but after an internal full-scale Calibration the value of the full-scale register is again exact hex 500000.
We test about 30pcs from the 75 and they have all the same properties.
Is this a failed charge ?