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Convert ADC Code to current in Amperometric measurement

Category: Software
Product Number: AD5940
Software Version: Keil5


I am looking into the code of amperometric for AD5940 and have two questions. Is ADCPgaGain adjustable during a single measurement? What I found the most confusing is the calculation of current. How is RtiaCalValue.Magnitude determined? I did not find it in the code. Attached is the relevant code. I really appreciate your answers.



  • Hi,

    1) After each measurement, you can change ADC PGA gain by updating it inside AppAMPRegModify() function by including below lines in it:

     DSPCfg_Type dsp_cfg;

    dsp_cfg.ADCBaseCfg.ADCPga = new PGA gain value;


    2) RtiaCalValue.Magnitude is the magnitude of calibrated value of internal RTIA resistor ( feedback resistor of LPTIA). 

    This calibration is done by AppAMPRtiaCal() function.

     AppAMPRtiaCal() function needs RTIA value input from user which is set by AppAMPCfg.LptiaRtiaSel.