I recently ran into a problem with the reference detect on the AD7193. Reference Detect is not working properly on Ch3 only. I posted one sample of hex output from 4 independent AD7193s on the same pcb. All channels are open circuit reference.
As you can see from the status append on channel 3 (43 = error + ch3) the ADC recognizes there is an error, but does not reliably set the data all high nor does it set the NOREF bit (63 = error + noref + ch3). Is there something special about Ch3? Is there something else i might have set wrong?
I just tried something new. When the temperature sensor is turned off, the reference detect works on Ch3. Any ideas why the temperature sensor might interfere with the reference detect only on ch3?