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  1. #1
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    Question about ADC resolution

    Hi~~
    If said a ADC has 12bits,then the reference voltage = 2V
    then the smallest can measured voltage = 2/(2^12) = 4.88mV (it means LSB) ,
    and if reference voltage = 1 V --> 1/(2^12) = 2.44mV ,
    so the reference voltage =1 can measure smaller voltage if ADC's bit =12

    Is this statement is right?
    thanks~~~

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  2. #2
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    Re: resolution of ADC?

    yes, you are right, but be carefull, erros in
    ADC are a minimun arround a fixed Vref value
    take a look at MCP3204 datasheet figure 2-12
    page 7 (ds21298c.pdf from www.microchip.com)



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  3. #3
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    resolution of ADC?

    you are correct only if your adc is not noise limited when the reference scales down



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  4. #4
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    Re: resolution of ADC?

    Quote Originally Posted by chungming
    Hi~~
    If said a ADC has 12bits,then the reference voltage = 2V
    then the smallest can measured voltage = 2/(2^12) = 4.88mV (it means LSB) ,
    and if reference voltage = 1 V --> 1/(2^12) = 2.44mV ,
    so the reference voltage =1 can measure smaller voltage if ADC's bit =12

    Is this statement is right?
    thanks~~~
    Take care 2/(2^12) = 0.488mV. So pay attention to niose.



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