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~~~ •

2. 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) •

3. resolution of ADC?

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

4. Re: resolution of ADC? 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. --[[ ]]--