Electronics © by DR. M. Amer

9/3/2015 Course Contents Introduction Introduction Fundamentals of Semiconductor Devices Fundamentals of Semiconductor Devices P-N Junction Diodes P-N Junction Diodes Bipolar Junction and FET Structures Bipolar Junction and FET Structures Semiconductor Devices(circuit element, filter, power supply, rectification amplifier) Semiconductor Devices(circuit element, filter, power supply, rectification amplifier) Introduction to digital circuits. Introduction to digital circuits.

Introduction Introduction 9/3/2015 electronics fundamentals

Very large and very small numbers are represented with scientific and engineering notation. Scientific and Engineering Notation 47,000,000 = 4.7 x 10 7 (Scientific Notation) = 47 x 10 6 (Engineering Notation)

= 2.7 x (Scientific Notation) = 27 x (Engineering Notation) = 6.05 x (Scientific Notation) = 605 x (Engineering Notation) Scientific and Engineering Notation

SI Fundamental Units Length Mass Time Electric current Temperature Quantity Unit Symbol Meterm Kilogram kg Seconds AmpereA KelvinK

Some Important Electrical Units Except for current, all electrical and magnetic units are derived from the fundamental units. Current is a fundamental unit. Current Charge Voltage Resistance AmpereA CoulombC VoltV Ohm  WattW Quantity Unit Symbol Power These derived units are based on fundamental units from the meter- kilogram-second system, hence are called mks units.

Engineering Metric Prefixes peta tera giga mega kilo P T G M k Can you name the prefixes and their meaning?

Engineering Metric Prefixes milli micro nano pico femto m  n p f Can you name the prefixes and their meaning?

When converting from a larger unit to a smaller unit, move the decimal point to the right. Remember, a smaller unit means the number must be larger. Metric Conversions 0.47 M  = 470 k  Larger number Smaller unit

When converting from a smaller unit to a larger unit, move the decimal point to the left. Remember, a larger unit means the number must be smaller. Metric Conversions 10,000 pF = 0.01  F Smaller number Larger unit

When adding or subtracting numbers with a metric prefix, convert them to the same prefix first. Metric Arithmetic 10,000  + 22 k  = 10,000  + 22,000  = 32,000  Alternatively, 10 k  + 22 k  = 32 k 

When adding or subtracting numbers with a metric prefix, convert them to the same prefix first. Metric Arithmetic 200  mA = 200  A + 1,000  A = 1,200  A Alternatively, m  mA = 1.2 mA

Voltage is Review of V, I, and R the amount of energy per charge available to move electrons from one point to another in a circuit and is measured in volts. Current is the rate of charge flow and is measured in amperes. Resistance is the opposition to current and is measured in ohms.

The most important fundamental law in electronics is Ohm’s law, which relates voltage, current, and resistance. Georg Simon Ohm ( ) formulated the equation that bears his name: What is the current in a circuit with a 12 V source if the resistance is 10  ? 1.2 A Ohm’s law

If you need to solve for voltage, Ohm’s law is: What is the voltage across a 680  resistor if the current is 26.5 mA? 18 V

Ohm’s law If you need to solve for resistance, Ohm’s law is: 115 V What is the (hot) resistance of the bulb? 132 

Application of Ohm’s law The resistor is green-blue brown-gold. What should the ammeter read? 26.8 mA

In electrical work, the rate energy is dissipated can be determined from any of three forms of the power formula. Energy and Power Together, the three forms are called Watt’s law.

What power is dissipated in a 27  resistor if the current is A? Given that you know the resistance and current, substitute the values into P =I 2 R. Energy and Power

What power is dissipated by a heater that draws 12 A of current from a 120 V supply? The most direct solution is to substitute into P = IV. Energy and Power

What power is dissipated in a 100  resistor with 5 V across it? The most direct solution is to substitute into. 2 V P R  It is useful to keep in mind that small resistors operating in low voltage systems need to be sized for the anticipated power. Energy and Power

Ampere-hour Rating of Batteries Expected battery life of batteries is given as the ampere- hours specification. Various factors affect this, so it is an approximation. (Factors include rate of current withdrawal, age of battery, temperature, etc.) How many hours can you expect to have a battery deliver 0.5 A if it is rated at 10 Ah? 20 h

Electronics 225 Passive Components ResistorsCapacitorsInductorsDiodes Interface components

Electronics 226 Resistors Values specified in ohms (Ω), kilo-ohms (K), or mega-ohms (M) Marked with value using a code % 10%

Resistor Color Code Or how to read those little resistors!

Resistor Color Code 1 st band color gives 1 st number 2 nd band color gives 2 nd number 3 rd band color gives # of zeros 4 th band color gives tolerance or ±

How to read it - Resistors are color coded for easy reading. - To determine the value of a given resistor look for the gold or silver tolerance band and hold the resistor with this band to the right. Then read the colored bands left to right.

How to read it - Look at the 1st color band and determine its color. This maybe difficult on small or oddly colored resistors. Now look at the chart and match the "1st & 2nd color band" color to the "Digit it represents". Write this number down.

How to read it - Now look at the 2nd color band and match that color to the same chart. Write this number next to the 1st Digit. - Match the 3rd color band with the chart under multiplier. This is the number you will multiple the other 2 numbers by. Write it next to the other 2 numbers with a multiplication sign before it.

How to read it Example: First color is red which is 2 Second color is black which is 0 Third color is yellow which is 10,000 Tolerance is silver which is 10% Therefore the equation is: 2 0 x 10,000 = 200,000 Ohms ± 10% 2 0 x 10,000 = 200,000 Ohms ± 10%

Resistor Color Code Chart

K or M? - Many resistors have large amounts of resistance, so we use prefixes to have a handy short name - “k” is for kilo and means 1000 times - “M” is for mega and means 1,000,000 times (million)

Practice If you have an Orange Orange Brown Gold resistor What is it’s resistance? The first orange means 3 The second orange means 3 The brown means 1 zero The gold means ± 5% So answer is 330 ohms ± 5%

36 Capacitors Values specified in microfarads (μF) or picofarads (pF) Marked with actual value or a numeric code Some varieties are +/- polarized

37 Capacitor types Ceramic disk Monolithic ceramic Dipped silvered-mica Mylar or polyester Aluminum electrolytic (+/-) Tantalum (+/-) Ceramic diskMonolithic ceramicDipped siver-micaMylar Solid tantalum, polarizedRadial aluminum electrolyticAxial aluminum electrolytic

38 Inductors Values specified in henries (H), millihenries (mH) and microhenries (μH) A coil of wire that may be wound on a core of air or other non-magnetic material, or on a magnetic core such as iron powder or ferrite. Two coils magnetically coupled form a transformer.

39 Inductor types Molded inductor & air-wound inductorAdjustable air-wound inductor Ferrite core toroidal transformerIron powder toroidal inductorAir wound inductor

LSU 06/04/ Interface components SwitchesPlugsSockets Panel controls

LSU 06/04/2007Electronics 241 Two common plug styles RCA plug Shield Tip 1/8” stereo phone plug 1/8” mono phone plug Sleeve Ring Tip Sleeve Tip

What Is a Semiconductor? Many materials, such as most metals, allow electrical current to flow through themMany materials, such as most metals, allow electrical current to flow through them These are known as conductorsThese are known as conductors Materials that do not allow electrical current to flow through them are called insulatorsMaterials that do not allow electrical current to flow through them are called insulators Pure silicon, the base material of most transistors, is considered a semiconductor because its conductivity can be modulated by the introduction of impuritiesPure silicon, the base material of most transistors, is considered a semiconductor because its conductivity can be modulated by the introduction of impurities

Semiconductors A material whose properties are such that it is not quite a conductor, not quite an insulator Some common semiconductors elemental Si - Silicon (most common) Ge - Germanium

Insulators, Semiconductors, and Metals n This separation of the conduction bands determines the electrical properties of the material n Insulators have a large energy gap –electrons can’t jump to conduction bands –no current flows n Conductors (metals) have a very small (or nonexistent) energy gap –electrons easily jump to conduction bands due to thermal excitation –current flows easily n Semiconductors have a moderate energy gap –only a few electrons can jump to the conduction band »leaving “holes” –only a little current can flow