ABSTRACT
Almost every modern instrumentation system includes some form of digitizer, or analog-to-digital converter (ADC). An ADC converts real-world signals into digital numbers so that a computer or digital processor can acquire signals automatically, store and retrieve information about the signals, process and analyze the information, and display measurement results. Sampling is the process of picking one value of a signal to represent the signal for some interval of time. Normally, digitizers take samples uniformly in time, e.g., every microsecond. It is not necessary to sample uniformly, but doing so has some interesting and convenient mathematical properties. The process of digitization is not complete until the sampled signal, which is still in analog form, is reduced to digital information. An ADC quantizes a sampled signal by picking one integer value from a predetermined, finite list of integer values to represent each analog sample.
