Analog and Digital Conversion/ADC Converters

ADC Converter Steps

An Analog to Digital Converter (ADC) takes an analog input signal and converts the input, through a mathematical function, into a digital output signal. While there are many ways of implementing an ADC, there are three conceptual steps that occur:

1. The signal is sampled.
2. The sampled signal is quantized.
3. The quantized signal is digitally coded.

Sigma-Delta ADC's

In systems that requires at least 16 bits of resolution, such as audio electronics, by far the most common type of ADC converter is the sigma-delta converter.

The sigma-delta converters, unlike other kinds of ADCs, never sample the signal at any particular point in time. Instead, the output digital number is a weighted average of the signal over the entire sampling time.

Further reading

• "Signals From Noise: Constructing SINCk Decimators With A Subtractor"[1] by Dave Van Ess