ADS1232REF: reading different values than expected

Part Number: ADS1232REF

Tool/software:

Hello, I'm working on ADS1232REF and writing this topic for confiming a situtation. I read different voltage values with unexpected ratios. such as with gain 64 and calibrated 20 mV to 20 grams and gave different voltages from terminal, here are the values I get

20 mV 25 mV 30 mV 35 mV
19,97 grams 23,97 grams 26,97 grams 29,75 grams

As you see there is a no ratio between this numbers. Also I tried with a loadcell (4 pins, differencial), and get unexpected values about mass calculation. I believe there might be a problem about my board. if I'm mistaken, can you explain why. the other issue is I gave 20 mV with differencial but read 10.05 mV in screen and desktop applicaiton. I'm sure that there is no problem in my signal generator because I measured the given voltage values with different osiloscope.

Thank you for your answers.

  • Hi durukan,

    It is a holiday in the US, please allow a delay on the response. Thanks for your understanding.

    BR,

    Dale

  • Hello Durukan,

    Please provide the raw ADC readings.  Should be a 24b signed integer.  Also, can you provide a screenshot of the schematic, including the bridge connections and the ADC?  It is also possible you are violating the common mode input voltage range of the ADC; a schematic will help verify if this is correct.

    Regards,
    Keith Nicholas
    Precision ADC Applications