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ADS7830: How much current the internal reference can supply to the external circuitry?

AlbertShi
Prodigy 30 points
Part Number: ADS7830

As topic. Thanks!

  • 0
    TI__Guru**** 181021 points
    Hi Albert,

    The internal reference of the ADS7830 is not intended to drive external circuitry. What are you looking to do with the reference voltage outside of the ADC?
  • 0 in reply to Tom Hendrick
    Prodigy 30 points

    Hi Tom,

    I try to use the internal reference for the external amplifiers reference before the ADC to achieve the ratio matric performance. 

  • 0 in reply to AlbertShi
    TI__Expert 5575 points
    Hi Albert

    It is not recommended to use internal reference of ADS7830 to drive external circuit.
    In your case you are using internal reference of the ADC for the external amplifier reference, the input bias current requirement from op-amp pin will not be much (Typically less than uA) and I think you should not see any performance degradation at 8 bit level.

    If you have a long trace from ADC REF pin to op-amp pin then I would recommend to have local decoupling at op-amp pin.
    Also please make sure ADC reference pin should have decoupling capacitor placed close to the pin (0.1uF to 1uF)

    Thanks & Regards
    Abhijeet