An analog-to-digital converter (ADC) is a device designed to transform an analog signal into a finite set of digital output codes.

To accurately capture the analog input signal, it is essential to sample it at a rate of at least twice the highest frequency present in the input signal. These sampled values are subsequently converted into digital numerical representations.

This conversion process inevitably introduces a small rounding error, commonly referred to as quantization error or quantization noise. To minimize this error, a sufficient number of digital codes must be used.