AD7792 readback is wrong

Hi, 

Can you share your schematic diagram please and register configuration?

Are you also using a ratio metric configuration? If you want to know more about RTD circuits, I would recommend to check CN-0383 (Rev. C) (analog.com) and also download https://www.analog.com/media/en/designtools/calculators/rtd_configurator_and_error_budget_calculator-rel1.0.0.exe 

This tool uses a much newer product AD7124 which I also recommend for new designs as it has better performance and more advanced features suitable for RTD sensing application. 

Thanks,

Jellenie

Hi,JellenieR

Thanks for your help,it's OK now,

I reset chip after power on.

Best regards,

Aaron.

Hi Aaron. 

Good to hear that you have solved the issue. Though I still recommend to configure your circuit in a ratiometric configuration for better accuracy. 

Thanks,

Jellenie