Keywords: signal sampling intelligent sensors digitization
Earlier in this series, we touched on one problem that can arise when sampling an analog signal, namely the problem of aliasing. There are three other issues with signal sampling to which we now turn our attention: digitization effects, finite register length effects and oversampling.So far, we've been assuming that all of the signals we are measuring are continuous analog values, i.e. our measurements are completely accurate. Even in the cases in which we have noise, the underlying assumption is that the measurement itself—for example the noisy sensor output voltage—is known precisely.
In reality, at least for a system that employs digital signal processing, that's not really true because the measured analog signals go through a process known as digitization that converts the analog signal to a corresponding numeric value that can be manipulated mathematically by a processor.
The issue that we face with digitization is that within any processing unit we have only a finite number of bits with which to represent the measured signal. For instance, let's assume that we want to sample a signal that varies between 0V and 5V.
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Design 101
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