Part Number: ADS8681
Hello Team,
I'm posting this on behalf of my customer.
ADS8681 configured work with bipolar voltage, range +/-0.625*Vref. All configuration registers are programmed accordingly. It converts DC very well. However, I missed something obvious and cannot find it. The device delivers conversion result of applied positive voltage with sign bit set to one. And negative voltage conversion result is without. Otherwise, conversion results are very precise. I cannot locate anything in the datasheet that points to output data format except a couple of lines in clause 7.3.8. And sign bit normally is to indicate negative range with sign bit set to one.
I did check ADC configuration by readback from ADC of each configuration words. All passed well including test modes. Adjusted ADC range and checked ADC results vs voltage. All works well. The only issue for me is a sign bit. ADC configured to work with bipolar voltage. Range is +/-0.625*Vref. And as mentioned below sign bit set for positive range and is zero for negative.
Regards,
Renan
