Digital circuits are circuits dealing
with signals restricted to the extreme limits of zero and
some full amount. This stands in contrast to analog
circuits, in which signals are free to vary continuously
between the limits imposed by power supply voltage and
circuit resistances. These circuits find use in "true/false"
logical operations and digital computation.
The circuits in this chapter make use of
IC, or integrated circuit, components. Such
components are actually networks of interconnected
components manufactured on a single wafer of semiconducting
material. Integrated circuits providing a multitude of
pre-engineered functions are available at very low cost,
benefitting students, hobbyists and professional circuit
designers alike. Most integrated circuits provide the same
functionality as "discrete" semiconductor circuits at higher
levels of reliability and at a fraction of the cost.