Analog-to-digital converter (ADC)
The operation of it begins with the analog signal (input) and occurs in three
phases.
a) Sampling.
Consists of converting the continuous signal into a series of discrete
analog signals at periodic intervals.
b) Quantization.
Each discrete analog signal is assigned to one of a finite number of
previously defined amplitude levels.
The amplitude levels are discrete values of voltage ranging over the full
scale of the ADC.
c) Encoding.
The discrete amplitude levels are converted into digital code,
representing the amplitude level as a sequence of binary digits.