why integrated circuits are used?

Answer 1

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A monolithic integrated circuit (also known as IC, microchip, silicon chip, computer chip or chip) is a miniaturized electronic circuit (consisting mainly of semiconductor devices, as well as passive components) which has been manufactured in the surface of a thin substrate of semiconductor material.

A hybrid integrated circuit is a miniaturized electronic circuit constructed of individual semiconductor devices, as well as passive components, bonded to a substrate or circuit board

Among the most advanced integrated circuits are the microprocessors, which control everything from computers to cellular phones to digital microwave ovens. Digital memory chips are another family of integrated circuit that is crucially important to the modern information society. While the cost of designing and developing a complex integrated circuit is quite high, when spread across typically millions of production units the individual IC cost is minimized. The performance of ICs is high because the small size allows short traces which in turn allows low power logic (such as CMOS) to be used at fast switching speeds.

ICs have consistently migrated to smaller feature sizes over the years, allowing more circuitry to be packed on each chip - see Moore's law. As the feature size shrinks, almost everything improves - the cost per unit and the switching power consumption go down, and the speed goes up. However, IC's with nanometer-scale devices are not without their problems, principal among which is leakage current (see subthreshold leakage and MOSFET for a discussion of this), although these problems are not insurmountable and will likely be solved or at least ameliorated by the introduction of high-k dielectrics. Since these speed and power consumption gains are apparent to the end user, there is fierce competition among the manufacturers to use finer geometries. This process, and the expected progress over the next few years, is well described by the International Technology Roadmap for Semiconductors, or ITRS.

Answer 2

Integrated circuits are used because it is far simpler to employ them as building blocks for various circuits than it would be to build something using all the individual little parts contained within an IC. Also, todays IC's are tailored to your power consumption and operation speed fairly nicely. For example: early IC's used to use TTL logic fairly extensively. It is true that there were a lot of linear circuits that were not TTL oriented. However, for complex designs, TTL circuitry used a lot of power. This was difficult for battery operated device designers to deal with. Along came CMOS design IC's which use miniscule amounts of power and the battery operated designers went wild. A similar jump in technology occurred when ordinary NPN and PNP transistors inside IC's were replaced with JFET transistors. This change produced an increase in operating speeds of one or two orders of magnitude.

While on the subject of speed of operation, it is not generally practical to build a discrete component circuit with leads between the components as short as those within an integrated circuit chip. In VHF/UHF/and Microwave circuits lead length is critical and long leads can even prevent the desired circuit operation. Similar benefits occur in switching circuits with the reduction of lead lengths. Signal propagation times are reduced.

Further advantages may be found in the uniformity of IC devices from unit to unit, as opposed to discrete component assemblies where aparently similar devices will often show widely differing characteristics as a result of minor individual component differences. So, when you utilize IC's, the probability of having a working end result is greater.

Lastly, if you build using IC's, troubleshooting/repair is much easier (assuming the device is manufactured in a repairable manner) because you can swap out whole modules (IC's) instead of working with individual diodes, resistors, capacitors and such of a discrete component design. For example: A Crystal Oscillator...
Discrete Design: Crystal plus about 6 to 12 components depending upon design.
IC Design: One tiny module with crystal built in and specifications guaranteed..

Answer 3

because through including tiny quantities of ideal aspects ('doping') the houses of the semiconductor could get replaced in diverse aspects of the semiconductor crystale. this enables structures stated as pn junctions to be made contained in the crystal; those are the mandatory aspects of diodes and transistors. The homes of metals can not be managed in this kind. See link

Answer 4

To simplify the connections involving the functions of the materials involve by making them compact and one unit to deal.