ABSTRACT
The advance of digital audio has greatly improved the fidelity of audio storage media, and generally made wonderful things possible, but sound waves remain stubbornly analogue, and so conversion from analogue to digital and vice-versa is very necessary. A most important consideration is to keep digital signals, particularly fast ones such as clocks, out of the analogue inputs, so use as much physical spacing between these as possible. Separate analogue and digital ground planes should be used. Most conversion ICs have their analogue and digital interfaces at opposite ends or opposite sides of the package, facilitating the use of separate ground planes. A typical application of analogue to digital converters (ADCs) is in digital mixing consoles. These must accept both microphone and line input levels. There are a large number of ADCs on the market, and it is necessary to pick out just a few to look at.
