Semiconductors

 

Semiconductor is material which have conductivity between insulator and conductor is called Semiconductor. In the periodic table some element of group from III-IV are Semiconductors. Usually used Semiconductor elements are Silicon, Germanium. In which Silicon is most used. because od high melting point up to 1420 and electron in outer most cell is 14. It can be find from rock and in form of sand from beaches.

• What is semiconductor?
• Feature of Conductor
• Feature of Insulator
• Feature of Semiconductors
• Atomic packing fraction
• Semiconductor fabrication technology
• Valence Bond, Conduction Bond
• Forbidden Energy Gap
• Types Of Semiconductors
• Electrons and Holes
• Extrinsic and Intrinsic
• N-type Semiconductors
• P-type Semiconductor
• Fermi Energy Level

History of C Language

C is most widely used programming languages of all time. Many latter languages have borrowed directly or indirectly from C, including C#, D, Go, Java, JavaScript, Limbo, LPC, Perl, PHP, Python and Unix C shell. In the earlier time every language was designed for some specific purpose.

For example FORTRAN(Formula Translator) for used for the scientific and mathematical applications, COBAL(Common Business Oriented Language) was  for the business applications.

The C language was development in 1970s at Bell laboratories by Dennis  Ritchie. Initially it was designed for the programming in the operating  system called UNIX. After the advent of C, the whole UNIX operating system was rewritten using it. Now entire UNIX operating is in C language tool supplied with it including the C compiler itself are written in C.

Mainly C language was derived from B language, which was written by Ken Thompson at AT & T Bell Laboratories. B language was adopted  from a language called BCPL (Basic Combined Programming Language), which was developed by Martine Richards at Cambridge University.

In the 1982 a committee was form by ANSI(American National Standard Institute) to standardize the C language. Before this there was an officially standard for C, many user and implementers relied on an informal specification contained in the book by Dennis Ritchie and Brain Kernighan, that version is generally referred as “K&R”C. Finally in 1989, the standard for the C language was introduced as ANSI C. Generally most of the modern compilers confirm conform to this.

• Basics Form of C Program

• First Program in C

Full form of Computer

 

Full form of Computer may be many type. Some of given bellow.

C = Common
O = Oriented
M = Machine
P = Particularly
U = United and used under
T = Technical and
E = Educational
R = Research

 

An other full form may be like following.

C = Commonly
O = Operating
M = Machine
P = Purposely
U = Use for
T = Teaching
E = Entertainment &
R = Research

 

And also may be like.

C = Commonly
O = Operated
M = Machine
P = Particularly
U = Used for
T = Technical &
E = Educational
R = Research.

Internal Structure of Computer

 

Conventionally, a computer consist at least----

• Central Processing Unit (CPU)
• Memory (RAM & ROM)
• Peripheral Devices(I/P & O/P)

Central processing Unite is main component of Computer. We can call it mind of computer. It responsible for all the task happen in computer. It perform the Arithmetic and Logical operation with the help of ALU (Arithmetic & Logic Unite). According to the command given through the input device it perform the operation.

Memory used for store the data like instruction and logical sets and movie and song and pictures. In the computer there are two type of memory is used.

• RAM
• ROM

RAM-Random Access Memory = It is volatile memory. Volatile stand here for that when we off the power then it will be erase automatically. It is in use until the system is on. It increase the speed of system. It have capability to store data temporary which is currently in use or may be use.

ROM-Read Only Memory = It’s called hard disk. All the item is store here in the ROM. When we install any program then instruction extract and all the supporting files were stored in hard disk, that is store in here we store here data in digital form, and according to the requirement supporting file supports the the operations.

In the peripheral devices two type devices come, output and input devices. For output we use monitor and projectors. And for the input we use the keyboard, mouse, pen drive, floppy, and CD etc.

Now the question is come in the mind is that how the system work?

Answer is given bellow-

Click here

BJT

 

Bipolar Junction Transistor stands for BJT. This is transistor, which is form after connecting two semiconductor of N-type or  P-type between two semiconductor of N-type or P-type. Mean when we have to form NPN Transistor then one P-type semiconductor is sandwich  between two N-type semiconductor. Same as when we have to form PNP Transistor then one N-type semiconductor is sandwiches between the two P-type semiconductor.

Structure of BJT is given bellow-

                       

 

• Introduction to Bipolar Polar Junction
• Working of BJT
• History of BJT
• Structure of BJT
• V-I Characteristics of BJT

MOSFET

 

The metal oxide semiconductor field effect transistor (MOSFET or MOS-FET) is transistor used for the amplifying or switching electronic.

Although MOSFET is four terminal devices with source (S), gate (G), drain (D) and body (B) terminal. As shown in the figure. Usually body is connected to source terminal, have less use, them it also become three terminal device like BJT. In the present time MOSFET leave back to BJT while BJT Transistors Integrated circuited work faster then MOSFET (BJT is faster then MOSFET) and reason is that small size and power consumption. MOSFET operating voltage is low then BJT, size is also small them there can fabricate large numbers of transistors on same chip size.

Thus in the present time number of transistor in chip going to increase every day is result of these technology.

• Introduction to MSFET
• History of MOSFET
• Fabrication of MOSFET
• MOSFET Operation

History of VLSI

 

Mainly VLSI was begin in the 1970s when the complex semiconductor and communication technologies were begin. It  is not a technology that not come in use in one night from sky.It developed stair wise sequentially one after one steps.

 

Now need to go in depth. In the starting of 1920 inventers wants to control currents in solids-state diodes and want to fabricate triodes. I like tell here that in that time Vacuum Tube were used efficiently.

After a long struggle inventers find their problems solutions. Discovery remain continue till the 1947. While in that time second world war was going on. In that world war scientists were use the Silicon and Germanium crystals as the Radar Detectors, and this was the turning point. That scientists turn towards solid-state development, and finally in 1947 Bell labs give a invention of Transistor which make a new revolution in the Electronic Field.

When the small component, transistor is made then it is thought that now it is possible that on a small size chip many number of
transistors can be produces through epoxidation method and that happen possible but problem was arises when the number of transistor is increases then main problem was the complexity  increases, that how the transistors connected to each other. Because all the component are time dependent and as the circuit increase speed will be slow and time will be take more for processing any task. So this was the solution that use a small circuit like chip on which all the component are connected
sharply to make small size of device and component.

And this problem was solved in 1958 by Jack Libly at Texas Instrument by making all the component on a single chip. That transistor was not as like as present time transistor. This was the manually connected on the same block of metal on single layer of silicon without wire, and it is produces in silicon wafer.

In the starting at 1960s in silicon wafer almost up to 10 transistors uses mean up to 10 transistors connected on one substrate that call Small Scale Integration(SSI) and then Large Scale Integration (LSI) come in use and after that in 1970 come
Very Large Scale Integration(VLSI). In the VLSI thousands numbers of transistors on a single chip were fabricated using wafer, and this call VLSI technology.

What is Microprocessor ?

Microprocessor is programmable single chip logic device that use to control any device or start or stop any device. On the other hand we can say that microprocessor is a data processing unit or data computing unit of computer.

Mean that Microprocessor is a programmable integrated circuited that have computing and decision making capability same as the Central Processing Unit (CPU).

Question- Application of Microprocessors in our daily life.?

We can see many application of Microprocessor in our daily life such as Lift system, petrol pump, ATM Machine and many more so that we can feel microprocessor a integral part of our life in the present time.

                                                                                                                                                  Click here

In the really the microprocessor is clock-driven semiconductor device consisting of electronic logic circuits manufactured by the using either a large –scale integration (LSI) or very-large-scale integration (VLSI) techniques. The microprocessor has capability of performing various computing functions and making decisions to change the sequence of program executions.

Basically a microprocessor contains  three main components -

1. Arithmetic / Logic Unit
2. Register Array
3. Control Unit

Microprocessor communicates and operates in the binary numbers 0 and 1 , called bits. Each microprocessor has a fixed set of instructions in the form of binary called Machine Language. And binary Instructions are given abbreviate names called mnemonics, which form the Assembly Language for a given Microprocessor.

Arithmetic / Logic Unite

click here

Register Array

click here

Control Unite

click here

C Programming Language

• Introduction to C Programming Language
• History of C Programming Language

Introduction to C Programming Language

Software is collection of program and a program is collection of instructions.

Development of software-

As the above diagram shown. before making any software first we see the user requirement and analysis on that problem and think that what is output and what is input. And then design the ALGORITHM.

ALGORITHM= > “Algorithm is sequence and step of program for solving the problem”

Programming Languages

1.    Low Level Language

2.    High Level Language

Low Level Language

1.    Machine Level Language2.    Assembly Language

Computer (Machine) understand only the binary number 0 and 1. And Machine language consist the instructions in the form of 0 and 1 that called the Machine level language. Computer understand only the Machine level language.

Main problem in writing the program in Machine language is that writing the program instructions in binary number. Machine level language is not portable. Every computer has it’s own machine instructions, so the program written for one computer is not valid for another Computer. Low level language work very fast.

We can say that Assembly Language is some advance version of Machine level language. And advance feature is that instructions are in the English word like “MOVE” “ADD” “SUB” etc. So it is easier to write. But Computer understand only Machine Level Language so there is use a Translator that called “ASSEMBLER”.

Writing the program in the Assembly language to keep in mind hardware structure. Here Assembly Language is not also portable because data stored in the Registers Set and each have different set of Registers, so we can say that Assembly language is not also portable.

History of Operating System

In the 1970’s , CP/M (Control Monitor Program) was the widely used operating system, it was designed for 8-bit processor such as the Z80 and 8085 and 8080A.

In the 1980’s when the 8-bit microprocessor were replaced by 16-bit processor in the personal computers (PCs), MS-DOS (Microsoft Disk Operating System) replace CP/M. MS-DOS (also known as DOD or PC-DOS) was designed to handle 16 bit processor system.

MS-DOS at that time was text-based operating system mean that command are written using keyboard to perform any task and operation. It was very very hard to operate because every operation and task need a specific command, which is very hard to learn a large numbers of commands.

So time latter in 1990’s Microsoft launch a graphical uses interface (GUI) operating system such as Window 3.1and 95. this type of window was enable the user to write commands by clicking on the icons rather then using then a keyboard. Mean in the icons commands are written earlier as click that command run and operation will be start to perform.

After then 32 and then 64-bit processor were launched then operating system such as UNIX, Linux, OS/2, Window 95/98/2000, ME (Millennium) and NT were launched.

Now a days Window XP/7 were launched with advance technology and feature. In the last of 2012 Window 8 were launched with new features an high speed then others windows.

History Of Microprocessor

Microprocessor is programmable single chip logic device that use to control any device or start or stop any device.

As we have describe the earlier about the WHAT IS THE MICROPROCESSOR ?

Revolution of Microprocessor being started with a bold and innovative approach after invention of Integrated Circuited. The First Microprocessor of the world was invented in 1971 name 4004 by Intel.

It is very interesting story, how the first microprocessor was designed. In 1969 Intel Corporation’s engineer “Ted Hoff” were working on designing a semiconductor memory. In 1969, Intel get a job to design a programmable calculator from a Japanese Company Bucsicom. But when the calculator is designed it original design have 12 different chip connected to each other to form that programmable calculator. So it have became big size then requirement. At that time Ted Hoff who was working in Intel (he was introduced 64-bit Semiconductor bipolar RAM chip) suggest about a general purpose single chip that can perform all the operations of that calculator and various logic functions, on the basics of 0_s and 1_s binary numbers provided to that single chip  which is keep stored in registers, at the appropriate timing. Group of Register is use to store any number in binary number form.

And thus way Intel successfully designed that programmable calculator withe help of single general purpose chip, and some time latter Intel got a idea is that this general purpose single chip have a quality of processing data store in group of registers and performing the various logical operations. And keep this idea in the mind Intel became successful to designed 4-bit microprocessor 4004 in 1971.

Question- What do you mean by 4-bit microprocessor ?

Answer-   Click here 

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And thus a way the improvement in the first designed microprocessor 4004 is started and Intel designed many advance versions of the processor likes……

Processor	Year of Introduction
4004	1971
4040	mid-1971
8008	1972
8080	1976
8086	1978
8088	1979
80286	1982
80386	1985
80486	1989
Pentium	1993
Pentium Pro	1995
Pentium II	1997
Pentium III	1999
Pentium 4	2000

It was not that only one company name Intel only designed the microprocessor. Motorola was the second company which also designed many microprocessors like…

Motorola 6800

Zilog Z80

Question- How the quality of performance of microprocessor is improved, while size remain same of the microprocessors.?

Answer- Click here 

History of Integrated Circuit [IC]

Before the 1960’s when the Integrated Circuited were not invented then the in place of Integrated Circuited a component name “Discrete Component” were used.

Question-What is Discrete Component ?

Answer-……………………………………………………………

While integrated circuited were small in size and consume less power then discrete components and it allow more transistors on a single chip which make more computing power and analytical to system in solving the any problem.

So We can say that “Integrated Circuited is single chip circuit which contain more number of transistors.”

HISTORY

History of Integrate Circuit is very interesting and sequence full. Mean as the science developed technology adapted that and make a new invention. As the same way first The Vacuum Tube were used in 1900’s.

In 1900’s Vacuum Tube Time

Then the in 1905 the first electronic diode vacuum tube is built by English physicist name “J. Ambrose Fleming. In this diode use the alternating current into the direct way signal. After then the in 1906 a American scientist name “Lee De Forest” made a vacuum tube such a type in that there is control and amplified the signal, from here the technology of electronics is born.

In 1940’s Starting of Transistors

First transistor were made in middle of 20_th century in 1947 at Bell Lab by “Bardeen”, “Shockley” and “Brattain”. With the help of point contact technology a BIPOLAR TRANSISTER is made. And then in 1951 JUNCTION FIELD EFFCT TRANSISTER (JFET) invented. And in 1952 single crystal silicon is fabricated. And such way as the science grow like Oxide masking is developed then technology adopted and  in 1958 first Integrated Circuited is built in Texas Instrument by the Jack Kilby, and this is starting of the Integrated Circuit fabrication.

And some time later there come a improvement by the Fairchild Semiconductor like Planner process in which first take a silicon layer and on that all the transistor are distributed, like passive oxide layer to protect the junctions.

And thus way different technology come like-

SSI- small scale integration (up to 20 gate per chip In1960)

MSI- medium scale integration (up to 20-200 gates per chip After 1060)

LSI- large scale integration ( up to 200-5000 gates per chip in 1070)

VLSI- very large scale integration ( > 5000 gates per chip in 1980)

Operating System