An ADC is an electronic system or a module that has
an
Analog Input (VIN), Reference Voltage Input
(VREF) and Digital Outputs. The ADC
converts
the analog input signal to a digital output value that represents the magnitude or value
of the analog input in comparison with the reference voltage. It
samples
the input analog voltage and produces an output digital code for each sample
measured.
Basic symbol of an ADC with input and output signals are as shown in the following
diagram.
Figure 1. Basic ADC Module
Let us understand a few basic terminologies and concepts used in the ADC before attempting to understand the working principle of an ADC.