An integrated circuit or IC, also known as chip or microchip is a set of electronic circuits on one small flat piece of semiconductor material usually silicon. The integration of large numbers of tiny MOS transistors into a small chip results in circuits that are many times smaller, faster and less expensive than those constructed of discrete electronic components. MOS refers to metal-oxide silicon which are commonly used in production of current integrated circuits. The IC’s mass production capability, reliability and building block approach to circuit design has ensured the rapid adoption of standardized ICs in place of designs using discrete transistors. ICs are used today in virtually every electronic component available to us, from phones to laptops, TV’s, cameras, smart refrigerators etc. Integrated circuits were made practical by advancements in metal- oxide silicon semiconductor fabrication. These advances have made the ICs considerably smaller while their computing power or processor speeds are millions of times greater than their predecessors of the 1960s and 70s. Integrated circuits have two advantages over their discrete counterparts being cost and performance. The cost is low because the chips and their components are printed as a unit of lithography rather being constructed one at a time. The performance of the ICs are high because the components switch quickly and consume comparatively little power because of their proximity and small size. The initial cost of design of the ICs is however high and therefore commercially viable when high production volumes are anticipated. Modern ICs contain billions contain billions of components and therefore to complex to be designed by hand, hence special tools are used for design and production.
Integrated circuits can be classified into analog, digital and mixed signals which consist of both analog and digital on the same circuit.
Digital ICs can contain billions of logic gates, flip flops multiplexers and other circuits mounted in a few square millimeters. The small size of these circuits allow high speed, low power dissipation and reduced manufacturing cost compared with board level integration. These digital ICs which include microprocessors and microcontrollers work using Boolean algebra to process ‘zero’ and ‘one’ signals. Among the most advanced integrated circuits are microprocessors which control everything from smartphones to laptops to digital microwave ovens. Digital memory chips and application specific integrated circuits are other examples of digital ICs. Programmable logic devices have also been developed which allow the user to program the logical function and connectivity of the built-in circuits.
Analog ICs such as sensors, power management circuits, and operational amplifiers operate by processing continuous signals. They perform analog functions such as active filtering, demodulation and fixing. These ICs ease the burden on circuit designers by having expertly designed analog circuits available rather than designing and constructing difficult analog digital circuits from scratch.
MIXED SIGNAL ICs
Ics can also combine analog and digital circuits on a single chip to create functions such as analog to digital converters and digital to analog converters. Such mixed signals circuits offer smaller size and lower cost but must be careful to avoid signal interference. Examples of such analog digital circuits include radio frequency chips such as Intel’s DECT cordless phone or Wi-Fi chips created by Atheros and other companies.