The fundamental difference between analog and digital
is ‘‘information.’’ With digital information the output is
always the same: a set of ones and zeros that represents
the information. This information is independent of the
supply voltages or the circuitry that is used to generate it.
With analog, the output information is basic electrical
values—volts, current, charge—and is always related to
some real world parameters.With analog, the methodology
used to arrive at the answers is intrinsic to the quality of
those answers. Errors such as temperature, noise, delay and
time stability can all affect the analog output and all are a
function of the circuitry that generates the output. It is this
analog output that is difficult to derive and requires experience
and circuit design talent.
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