How does the ICs(integrated circiut) works ? How they are being classified ?

Question

It is the question of semiconductor physics

Answer 1

Pick up a beginners book on them. This is no place to answer such a broad question.

Answer 2

An integrated circiut or an IC, is made up of semiconductor material as Silicon etc.
For undersatnding the working of an IC or for that matter anything in ELECTRONICS, one should know about signals. The signal maybe either HIGH(1) or LOW(0). Lets take an example of a bulb connected with a switch and a battery. The HIGH signal indicates that the bulb is glowing, while LOW signal indicates that the bulb is not glowing. For convinience we will consider HIGH signal as '1' and LOW signal as '0'.
Now, the IC consists of millions of gates inside which are basically classified into three groups namely-
1) Basic gates - NOT gate (inverter), AND gate, OR gate
2) Universal gates - NAND gate (AND+NOT gate), NOR gate (OR+NOT gate).
3) Exclusive gates - EX-OR gates & EX-NOR gates.
The working logic of the gates can be explained as follows...
Let us consider inputs as A, B, C and so on...
1) The function of NOT gate is to invert the signal. Which means that if the signal provided is HIGH the gate will invert the signal and show the output as LOW. i.e. if the input is 1 the output will be 0 and vice versa.
2) The working of AND gate can be easily understood by the following truth table
A B OUTPUT
0 0 0
0 1 0
1 0 0
1 1 1
From the above truth table clearly it is visible that when the two signals are HIGH then and then will the output be HIGH in an AND gate.
3) OR gate
Consider the truth table for OR gate
A B OUTPUT
0 0 0
0 1 1
1 0 1
1 1 1
For an OR gate we observe that the output is HIGH even if one of the input signals is HIGH.
Working of Universal gates-
4) NAND gate
NAND gate is nothing but the inversion of the AND gate signals. Consider the truth table of NAND gate
A B A'AND'B OUTPUT
0 0 0 1
0 1 0 1
1 0 0 1
1 1 1 0
We can clearly observe the inversion. Hence the name.
5) NOR gate
As in NAND gate NOR gate gives output showing the inversion of an OR gate. The truth table can be given as follows
A B A'OR'B OUTPUT
0 0 0 1
0 1 1 0
1 0 1 0
1 1 1 0
The truth table reveals clearly the inversion of the OR output. Hence the name.
Working of exclusive gates.
6) EX-OR gate
The gate is called as EXCLUSIVE-OR gate. The output of the EX-OR gate is seen clearly in the following truth table
A B OUTPUT
0 0 0
0 1 1
1 0 1
1 1 0
Output shows that when both the inputs are same, may it be both Low inputs or both HIGH inputs the output will be LOW. And when there is differential input then the output is HIGH.
7) EX-NOR gate
This is the EXCLUSIVE-NOR gate. It is nothing but the inversion of an EX-OR gate. The following truth table gives the output values.
A B OUTPUT
0 0 1
0 1 0
1 0 0
1 1 1

This was the working of the fundamental part of an IC. The IC contains millions of strategically realised gates inside it. The gates will work sequentially or by the path that is designed and the required output will be shown.

Answer 3

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

You can get every details on www.wikipedia.com