The voltage acquired by the AD7768-4 jumps between 0-4.069V

Hi ChinaUniversityofPetroleum ,

Can you please share the actual voltage in the input pins, and the schematic?
Are you providing bipolar supplies to the ADC?

Thanks,
Janine

Hi!No bipolar power supply is provided, only a single 5V power supply.The first image shows the signal pre-processing, but instead of going through the middle two chips, I went through the R70 and R92 resistors to the AD7768-4 chip.The second image shows the schematic of the AD7768-4

Hi Janine

Hi ChinaUniversityofPetroleum ,

Apologies for the delay.

Thank you for clarifying. What is the actual voltage input to the AIN pins? Can you share the output of the ADC in code?

Thanks,
Janine

Hi Jannine

We tested that when the IN- input voltage is greater than the IN+ input voltage, the output voltage of the AD7768 jumps between 0-4.096V。

Hi ChinaUniversityofPetroleum ,

Thanks. Is the AD7768 circuit you bought the evaluation board?

Please help clarify what the input voltage to the AIN pins are. If the output is jumping between 0 and 4.096, that could correspond to all 0s and all 1s. Can you verify in the DOUT pin? Also, how are you sending a sync pulse to the ADC?

A sync pulse is required upon power-up and after any configuration to the register settings.

You can provide this by any of the 3 methods below

Thanks,
Janine

4V to -4V were all tested.But when IN+ is greater than IN- voltage, the acquired voltage is normal, doesn't sync pulse affect this?