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  1. #1
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    Multiple ADC inputs connected together

    Hello ,

    I have seen a design with a micro controller having an internal 12 bit ADC.

    Here ADC are being used for supply rails monitoring and as well as sensor ( a simple R-divider ) voltage detection.

    I'm curious that the designer has connected 2 ADC inputs together to each signal input.

    Is this generally used?

    Will paralleling multiple ADC input (without any resistors in series ) cause any impedance problems?

    Any suggestions is welcome.

    Thank you,

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    Re: Multiple ADC inputs connected together

    Hi,

    I have seen a design..
    So why donīt you show it?

    Klaus
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  3. #3
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    Re: Multiple ADC inputs connected together

    Sorry I cannot upload image ..

    Basically it is nothing..

    2 ADC inputs shorted together connected to 3.3V / 5V buck regulator output capacitors through a R divider of 10k


    *******10k*******10k
    3.3V----\/\/\/\-- |---\/\/\/\----->GND
    *************|
    *************|
    *************|----> ADC CH1
    *************|----> ADC CH2

    Hope this helps,

    Thanks



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    Re: Multiple ADC inputs connected together

    Hi,

    Without additional information "paralleling of two ADC inputs" makes no sense.

    Thus I assume there is additional information.

    Why canīt you upload the image or give us the link to the source of your information?

    Klaus
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    Re: Multiple ADC inputs connected together

    Perhaps one or both of the pins have dual purpose and is used in digital mode. Taking two identical measurements makes no sense and the extra load on the source can do nothing but reduce accuracy. Some more info is needed, in particular what MCU it is.

    Brian.
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