ADS8638: ADS8638 accuracy issue

Hello,

To make sure I understand correctly. You are providing the same input signal to all input channels?  and the input signal is the power supply?

how is your input signal driven? what is the input source?

After making sure the hardware is all correct, we can look into software.

If the error is consistent across the device, you can do a calibration in software to take this into consideration

The following documents provides information on a two point calibration, though the focus of the documents are not calibration, it is well covered

Circuit to increase input range on an integrated analog front end (AFE) SAR ADC

Reducing effects of external RC filter circuit on gain and drift error for integrated analog front ends (AFEs): ±10V

Hi Cynthia,

Thank you for your information.

Yes, it is the same input signal to all input channels, and the input signal is from the power supply DC=5.00V.

My application is the ADC sensor (0~5V). This issue is around 50% on different devices.