Other Parts Discussed in Thread: REF6250, LM4120, REF6050, ADS8861, OPA376, THS4551, LM7705, OPA320
I wonder if anyone can help me. I am using the ADS8860 ADC and some of the boards I have had manufacturered are exhibiting a minimum reading that I can't seem to get rid of.
I have some boards that when presented with GND as the input read 0, but others that read 30-40. I have tried adding additional decoupling to the reference and the AVDD and DVDD lines but nothing seems to make any difference. The board has a switch to select between a 5V LM4120 and REF6250 reference, but adding decoupling after the switch makes no difference to the digital reading output by the ADC.
Any thoughts would be much appreciated.