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Issue with AIC3106 Reading

Gus Martinez
Mastermind 29481 points


I'm using the AIC3106 in 16-bit mode to sample a 230mVrms 50Hz waveform.  However, the ADC reads somewhere in the range of 252mVrms (11710/32768 * .707).  What can be source of this inaccuracy?

  • 0
    TI__Mastermind 28585 points

    Gus,

     

    Assuming the signal path in the AIC3106 is set for single ended input and all of the gain paths are set to 0 dB, this could be offset or gain error (or a combination of both). If the input is AC coupled, it is also necessary to look at the filter pole and see what the attenuation will be at the input frequency. Be sure to look at the actual component values due to tolerance vs. the just the theoretical values.

     

    Best Regards,

    Dave

  • 0 in reply to Converter Apps
    TI__Mastermind 29481 points

    The input is single ended and all gain paths are set to 0dB.  Is the level of error I am seeing in the range of "normal" offset and gain errors?  It seems rather high.  Any advice on what is the best way to measure & compensate for this error?

  • 0 in reply to Gus Martinez
    TI__Mastermind 28585 points

    Audio CODECs aren't designed, tested, or specified for DC specs. Offsets can be on the order of 10's of mV, gain error can also vary. 

     

    If this is an industrial application, it might be better to look at our precision converters that tightly spec, offset, gain error and drift.