Computer Interfacing

Conversion between digital and analogue

Note that several conversions are made for every cycle

of the input waveform; a sinewave input is shown in Fig-

ure 3.1, but the principle is correct whatever the nature

of the varying analogue input voltage. This process of

converting samples of the input at successive times is,

naturally, called sampling. The more samples taken dur-

ing the period of the input, the more accurately does the

digital data represent the nature of the analogue signal.

Obviously there is a limit to the number of times a signal

can be sampled in any given time period; also, the higher

the frequency of the analogue input, th