Resolution vs Accuracy of ADC

Updated Nov 2, 2023

Issue Details

My 24-bit module has a worse accuracy in the specification than the 16-bit module.

Solution

The resolution of an Analog to Digital Converter(ADC) is defined as the smallest change in the value of an input signal that changes the value of the digital output by one count.

The accuracy of a converter refers to how many bits, from conversion to conversion, are repeatable. That is, accuracy reflects how true the ADC’s output reflects the actual input. 

So the resolution and accuracy are two different parameters that may not be equal to each other.
 

Additional Information

However, with higher resolution systems (≥16 bits), the transfer function’s response will have a larger deviation from the ideal response. This is because the noise contributed by the ADC, as well as driver circuitry, can eclipse the resolution of the ADC. 
 

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