In a recent blog post on omzlo.com, [Alain] explains how they found a bug in the Arduino SAMD21 analogRead() code which causes the output to be offset by between 25 mV and 57 mV. For a 12-bit ADC ...
ZX-AD16BSAR5M40LP is a 16-bit Successive Approximation Analog-to-Digital Converter (ADC) that operates up to 5MS/s. The ADC achieves full 16bit linearity, thanks to an inbuilt calibration engine ...
The L55CSD16B16K IP consists of a 16-bit mono audio ADC with fully differential 1-channel mono audio input, 4-channel general purpose (GP) inputs and a digital microphone input. It also has an analog ...
Some Arduino boards, however, feature more advanced ADC chips with better resolutions (meaning, you get more precise values).