Tech Trill

An Integrated Circut (IC) is an electronic circut in which both the active and passive components are fabricated on an extremely small piece of silicon (called a chip).It is an integrated circut becz the components like transistors,diodes, resistors, etc. are an integral part of chip.Such a circut is different from a discrete circut in which the components are individually connected during assembly.


Digital IC's contain circuts whose input and output voltages are limited to two possible level (i.e) low (0) or high (1).
It is so becz digital signals are binary in nature.That is why, digital circuts are also know as switching circuts.
Digital IC's include circuts such as logic gates, flipflops, memories, counters, microprocessors, etc.

Depending on number of components fabricated on a single chip (i.e component density), IC's can be classified as SSI, MSI, LSI, VLSI.
1) Small Scale Integration (SSI) :-Small Scale Integration refers to IC's with less than 12 gates on the same                                chip. Examples include FlipFlops
2) Medium Scale Integration(MSI) :-Medium Scale Integration refers to IC's with 12 to 100 gates on the same chip.Examples include Adders, Registors, Counters, RAM's (Random Access Memory),
ROM's (Read only Memory), Code converters, Multiplexers, etc.
3) Large Scale Integration (LSI) :-Large Scale Integration refers to IC's with more than 100gates per chip.Examples include digital clock, calculators, etc.
4) Very Large Scale Integration (VLSI) :- Very Large Scale Integration refers to IC's with several hundered thousand gate per chip.Examples of VLSI IC's include Microprocessors, Memories, etc.

In the manufacturing of IC's two techniques are used :-
1) Bipolar techonology.
2) Metal Oxide Semiconductor(MOS) techonology.

The bipolar techonology fabricates bipolar transistors on a chip.It is faster one and is preffered for SSI and MSI.
The MOS techonology fabricates MOS Field Effect Transistor on a chip MOS techonology dominates the LSI and VLSI fields because more MOSFET's can be packed into the same chip area.That is component density is more in MOS IC's, but it is slower one.