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PCM4222: gain and reference tempco

Mark Peting
Prodigy 10 points
Part Number: PCM4222

We are using this part in a measurement system for precision audio measurement.  We are trying to bound limits of measurement change between calibration procedures.  However the data sheet for the part doesn't have any temperature coefficient information for either input gain or the reference voltage, which would allow information about effects of temperature change.  Is this available for this part?  Of course any ageing information would be of interest as well.

  • 0
    TI__Mastermind 23030 points

    I can gather the below from the datasheet: i have no additional information and am not sure if this helps you.

    Output offset error  3mv

    Offset Drift 3uv/degree C

    There is some ambiguity here. I think it might  mean one of 2 things..

    1. It might be referring to the output offset of the  Buffers that drive the V com l or V com r pins with a DC reference voltage of 1.95v for a 4v Supply. This  voltage is generally given to a fully differential amplifier that is externally connected and defines the common mode voltage at the output of the external  Amp..  

    A 3mv  offset from 1.95v  at the output of the external  amp would appear at both the inputs of the PCM4222 chip and cancel out leaving no temperature effect.

    2.  It might refer to an offset signal presented to the ADC . If so the 3uv/deg drift would give a temperature dependent effect. a 50 deg change would give a 0.15mv additional singal..