RelayRelay

Vacuum Tubes and CRTVacuum Tubes and CRT

Individual TransistorsIndividual Transistors

Integrated Circuit (IC)Integrated Circuit (IC)

PCB BoardPCB Board

Masks, Ingot, WafersMasks, Ingot, Wafers

Chips, BoardsChips, Boards

Video: Video: TransitorizedTransitorized

The Bipolar NPN TransistorThe Bipolar NPN Transistor

The base-emitter junction is forward biased, the base-collector junction is reverse biased.

The transistor is bipolar because both charge carriers (holes and electrons) are present.

Fabricating a transistor on a Fabricating a transistor on a single piece of doped siliconsingle piece of doped silicon

wikipedia

CNN.com

Basic Amplifier Circuit using the Basic Amplifier Circuit using the NPN Bipolar TransistorNPN Bipolar Transistor

http://www.tpub.com

Model of first Transistor c. Model of first Transistor c. 19471947

http://www.porticus.org/bell

The Field Effect Transistor The Field Effect Transistor (FET)(FET)

Electricity Electricity flows from flows from the Source the Source to the to the Drain when Drain when an electric an electric field is field is applied to applied to the Gate.the Gate.

Field Effect Transistor (FET)Field Effect Transistor (FET)

FETs are tiny FETs are tiny switches that can switches that can open and close open and close very quickly.very quickly.

A negative A negative voltage will turn voltage will turn this p-channel this p-channel transistor on. transistor on. ‘On’ means there ‘On’ means there is a connection is a connection between the between the Source and Drain.Source and Drain. http://www.answers.com

Before the transistor, there was Before the transistor, there was the Vacuum Tubethe Vacuum Tube

►Also used to Also used to amplify signalsamplify signals

►Also used as a Also used as a switchswitch

Electrons are “boiled” off the cathode andattracted to the anode because of the applied voltage.

A grid controls the electron flow.The signal to be amplified is connectedto the grid. A small signal controls a much current.

http://www.privateline.com

Cathode Ray Tube (CRT)Cathode Ray Tube (CRT)Still is use TodayStill is use Today

►Vacuum Tube, Electron Gun, Fluorescent Screen, and Vacuum Tube, Electron Gun, Fluorescent Screen, and Coils which accelerate and deflect the electron beamCoils which accelerate and deflect the electron beam

►MagnetronMagnetron►Power AmplifiersPower Amplifiers

ENIAC in 1946ENIAC in 1946► First electronic First electronic

computercomputer► Designed for the Designed for the

ArmyArmy► $500,000$500,000► 19,000 Vacuum 19,000 Vacuum

TubesTubes► 1000 Relays1000 Relays► 200 KW of power200 KW of power► Filled multiple Filled multiple

rooms (700 sq. ft)rooms (700 sq. ft)► Soldered and Soldered and

constructed by hand constructed by hand by the University of by the University of Penn.Penn.

► SlowSlow► UnreliableUnreliable

Hearing Aids - the first Hearing Aids - the first commercial devices that used commercial devices that used

transistorstransistorsc. 1953c. 1953

http://blog.modernmechanix.com

► Individual PartsIndividual Parts► Integration of parts required hand wiringIntegration of parts required hand wiring

Early Sony Transistor Radio

Richard FeynmanRichard Feynman

As told to American Physical Society in As told to American Physical Society in 1959,1959,

'People tell me about miniaturization, and how far it has progressed today. 'People tell me about miniaturization, and how far it has progressed today. There is a device on the market by which you can write the Lord's Prayer There is a device on the market by which you can write the Lord's Prayer on the head of a pin. But that's nothing . Why can we not write the entire on the head of a pin. But that's nothing . Why can we not write the entire

24 volumes of the 24 volumes of the Encyclopedia Britannica on the head of a pin?Encyclopedia Britannica on the head of a pin?

  Feynman asked why wires couldn’t be 90 nm

The birth of the integrated The birth of the integrated circuit (IC)circuit (IC)

► 1947- using silicon as a transistor is discovered1947- using silicon as a transistor is discovered► 1959- Texas Instruments put 10 transistors on one piece 1959- Texas Instruments put 10 transistors on one piece

of silicon. First company to use Silicon instead of of silicon. First company to use Silicon instead of GermaniumGermanium

► Used in Apollo Program to achieve moon landing – Used in Apollo Program to achieve moon landing – transistors integrated on pieces of silicon offered lower transistors integrated on pieces of silicon offered lower power and weight. 1961-69power and weight. 1961-69

Moore’s Law Moore’s Law (Gordon Moore – Intel Founder)(Gordon Moore – Intel Founder)

Intel 4004

The World’s first Microprocessor, made in 1971

Computer on a chip!

It had 2300 transistors and ran at 740 KHz.

It could execute 45 instructions.

Could execute 96,000 instructions per second

As powerful as the ENIAC

Where’s the chip?Where’s the chip?

http://www.computerhistory.org/semiconductor/

http://www.britannica.com

Chips can have up to a billion transistors built on a small piece of silicon.

CMOS stands for ‘Complimentary Metal Oxide Semiconductor’. This means CMOS chips contain both pMOS and nMOS transistors.

Integrated Circuit Integrated Circuit Manufacturing Manufacturing

ProcessProcess

Clean Room

Masks, Photoresist, & a developing Masks, Photoresist, & a developing process called process called PhotolithographyPhotolithography

transfers patterns to the wafertransfers patterns to the wafer

http://chem.chem.rochester.edu

http://info.tuwien.ac.at

What do computers do?What do computers do?►Very simple operationsVery simple operations

Every computer has a small set of simple Every computer has a small set of simple instructions it can perform (Instruction instructions it can perform (Instruction Set)Set)

►Operate on 1’s and 0’s (binary data)Operate on 1’s and 0’s (binary data) Numbers are represented with 1’s and 0’sNumbers are represented with 1’s and 0’s Letters, symbols, & keystokes are Letters, symbols, & keystokes are

represented with 1’s and 0’s.represented with 1’s and 0’s.

►Do the operations very fastDo the operations very fast►Complex operations are broken down Complex operations are broken down

into many VERY simple operations.into many VERY simple operations.

Modern Computers might Modern Computers might process 64 bits at a timeprocess 64 bits at a time

0101010001110101001010101010101010100010010101000101010100101100

1110000101010101010100000101010100001011101001011101010101010101

1010100101011101101000101011101010101110100101000001011011111011

1011111010010000010101101010110101010101011110010101000101010010

Etc.

Binary Codes are base-2 Binary Codes are base-2 numbersnumbers

2097 2097 2 X 10 2 X 1033 + 0 X 10 + 0 X 1022 + 9 X 10 + 9 X 1011 + 7 X 10 + 7 X 1000 = 2,097 = 2,097

versusversus

1011 1011 1 X 8 + 0 X 4 + 1 X 2 + 1 X 1 = 11 1 X 8 + 0 X 4 + 1 X 2 + 1 X 1 = 11

ASCII ASCII (American Standard Code for Information Exchange)(American Standard Code for Information Exchange)

Each letter, punctuation mark, etc. has a unique 8-bit code.Each letter, punctuation mark, etc. has a unique 8-bit code.

0010011000100110 0101010101010101 00101110 00101110 FUN FUN

The Declaration of Independence, your love letters and emails, the The Declaration of Independence, your love letters and emails, the Bible are huge numbersBible are huge numbers..

http://jvsc.jst.go.jp

Analog sound waves can be stored directly in their analog form, e.g. by cutting grooves on vinyl.

http://www.optics.rochester.edu

All data can be digitized with out degradation over time.

www.bbc.co.uk

http://photo.net/equipment/digital/basics

Photographic picture is an analog image. The photo represents the original image. Note there is a continuous range of hues and shades in negative film. Copying from analog data usually results in loss of data. Copies from copies do not look as good as originals.

A digital image is made up of many pixels, each pixel having one color out of a fixed number of possible colors.

Each pixel is a digital number. Copying does not result in loss of data.

Data can be converted to binary Data can be converted to binary (digitizing) using an (digitizing) using an

analog to digital converteranalog to digital converterPeriodically Periodically take a sample, take a sample, at a rate of at at a rate of at least ½ the least ½ the frequency. frequency. The more The more samples the samples the more more information is information is captured. The captured. The more bits used more bits used the closer the the closer the sample sample approximates approximates the original.the original. /www.webbasedprogramming.com

Logical ‘AND’Logical ‘AND’

Example:Series Circuit with battery, two switches and a light bulb.

Logical ‘OR’Logical ‘OR’

Example:Two switches in parallel, with a bulb and battery.

Inverter or NOT gateInverter or NOT gate

Example:Series circuit with switch in parallel with bulb.

NAND and NORNAND and NOR

Not-AND NAND

Not-OR OR

Easier to make than AND and OR

MOSFET Transistor as a MOSFET Transistor as a SwitchSwitch

PNP type – negative voltage (a ‘0’) turns this transistor “on”

NPN type – a postive voltage (a ‘1’) turns this transistor “on”

http://www.iclayoutonline.com

Transistors perform logical Transistors perform logical operationsoperations

Build a Truth Table for this Circuit:

Exclusive OR (XOR)Exclusive OR (XOR)

•Inequality Tester•1-Bit Adder

Only 16 transistors

XORs and NOR make an XORs and NOR make an equality testerequality tester

A1B1

A2B2

How could this circuit be used to implement your word processors ‘search’ function? How would you find “FUN” in your document?

XORs, ANDs, and OR make XORs, ANDs, and OR make an Adder Circuitan Adder Circuit

SummarySummary Transistors act like on/off Transistors act like on/off

switchesswitches Computers operate on long Computers operate on long

words (64 bits) of 1’s and 0’swords (64 bits) of 1’s and 0’s Sophisticated operations can be Sophisticated operations can be

broken down into many very broken down into many very simple operations.simple operations.

Complex circuits are built from Complex circuits are built from simpler circuits (Equality Tester simpler circuits (Equality Tester made from XOR and NOR)made from XOR and NOR)

Basic logic operations are done Basic logic operations are done with a few transistor.with a few transistor.

Modern computers could be Modern computers could be made with mechanical relays.made with mechanical relays.

SourcesSources

http://www.pbs.org/transistor/