c. The Hybrid IC.
The monolithic and thin film processes are sometimes
combined to make a hybrid IC.
The resulting hybrid can have the high-quality
and capacitors formed in the thin film process.
Hybrid IC's are also made by
mounting individual chips, connected by fine wires, in the same package.
method, called the chip and wire method, is shown in figure 3-10. It allows more
complicated circuitry and improves isolation between components.
A chip and wire hybrid IC.
Originally conceived for military equipment, IC's are now
also being used in commercial products ranging from automobiles to hearing aids.
Basically, IC's are divided into two categories--linear and digital.
(1) Linear. Linear, or analog, IC's produce outputs directly proportional
to their inputs. They are used for transmitter and receiver circuits,
such as amplifiers (audio, video, AF, and IF), squelch switches,
mixers, oscillators, and other linear circuit functions.
IC's must be custom-made because the requirements of each circuit are
Figure 3-11 shows a partial schematic of a radio
receiver that uses linear IC's. The IC's are represented by triangles,
and the lines extending from them represent the leads to the IC
package. In the blown-up portion of the figure, you see the detailed
schematic of the IF amplifier.
Although the IF amplifier contains 13
different components, it requires no more space than a conventional
Because of this and the fact that IC's need so little
power to operate, some of the larger communication systems of today
will be reduced to manpack size in the future.
Digital IC's perform switching functions in logic circuits.
Because digital IC's operate with low power, are used thousands of
times in the same form, and can operate effectively despite loose
entire circuit is contained in a single monolithic chip, and is used in
One big advantage of digital IC's over
conventional digital circuits is that they operate faster.
digital IC's can operate in 400 trillionths of a second.