SEMICONDUCTORS, DIODE CHARACTERISTICS, AND APPLICATIONS

SEMICONDUCTORS

MATERIALS WITH ELECTRICAL PROPERTIES THAT LIE BETWEEN CONDUCTORS AND INSULATORS

SILICON AND GERMANIUM

TWO OF THE MOST COMMONLY USED SEMICONDUCTIVE MATERIALS ARE ____

VALENCE ELECTRON

PLAYS A CRUCIAL ROLE IN THE ABILITY TO CONDUCT ELECTRICITY UNDER CERTAIN CONDITION

4

BOTH SILICON AND GERMANIUM ATOMS HAVE ___ VALENCE ELECTRON

14

SILICON HAS ___ PROTONS IN ITS NUCLUES

32

GERMANIUM HAS ___ PROTONS IN ITS NUCLUES

CRYSTAL LATTICE

WHEN CERTAIN ATOMS COME TOGETHER TO FORM A SOLID MATERIAL, THEY ARRANGE THEMSELVES IN A FIXED, REPEATING PATTERN

COVALENT BOND

FORMED WHEN ATOMS SHARE THEIR VALENCE ELECTRONS WITH NEIGHBORING ATOMS

CHEMICAL STABILITY

ACHIEVED WHEN A SHARING OF ELECTRONS EFFECTIVELY GIVES EACH ATOM ACCESS TO EIGHT VALENCE ELECTRONS

1.1eV

BANDGAP OF SILICON

0.67eV

BANDGAP OF GERMANIUM

HIGHER BANDGAP

ALLOWS SILICON DEVICES TO OPERATE AT HIGHER TEMPERATURES AND WITH LOWER LEAKAGE CURRENTS, MAKING THEM MORE SUITABLE FOR A WIDE RANGE OF APPLICATIONS, INCLUDING HIGH-POWER AND HIGH-TEMPERATURE ENVIRONMENT

BETTER THERMAL STABILITY

SILICON’S HIGHER BANDGAP ALSO CONTRIBUTES TO ITS ____, WHICH MEANS THAT IT CAN WITHSTAND HIGHER TEMPERATURES WITHOUT SIGNIFICANT DEGRADATION IN PERFORMANCE THAT IS CRUCIAL FOR MANY ELECTRONIC APPLICATION

LOWER INTRISIC CARRIER CONCENTRATION

MEANS LOWER LEAKAGE CURRENTS AT ROOM TEMPERATURE, WHICH IS IMPORTANT FOR MAINTAINING THE EFFICIENCY AND PERFORMANCE OF ELECTRONIC DEVICES

RADIATION HARDNESS

PROPERTY OF SEMICONDUCTORS WHERE IT TENDS TO BE MORE RESISTANT TO RADIATION DAMAGE MAKING IT MORE SUITABLE FOR USE IN ENVIRONMENTS WHERE RADIATION EXPOSURE IS A CONCERN, SUCH AS IN SPACE APPLICATION

DOPING

A PROCESS WHERE IMPURITIES ARE ADDED TO SEMICONDUCTORS TO ENHANCE THEIR CONDUCTIVITY

NEGATIVE

N

POSITIVE

P

5

N-TYPE SEMICONDUCTORS ARE FORMED BY ADDING PENTAVALENT IMPURITIES WITH ___ VALENCE ELECTRONS

3

P-TYPE SEMICONDUCTORS ARE FORMED BY ADDING TRIVALENT IMPURITIES WITH ___ VALENCE ELECTRONS

PENTAVALENT IMPURITIES

IMPURITIES THAT DONATE AN EXTRA ELECTRON, INCREASING CONDUCTION-BAND ELECTRONS

TRIVALENTIMPURITIES

IMPURITIES THAT CREATE HOLES IN THE CRYSTAL STRUCTURE, INCREASING HOLE CONCENTRATION

ELECTRONS

MAJORITY CARRIERS OF N-TYPE SEMICONDUCTORS

HOLES

MAJORITY CARRIERS OF P-TYPE SEMICONDUCTORS

DOPING

ALLOWS PRECISE CONTROL OVER CONDUCTIVITY BY ADJUSTING THE NUMBER OF IMPURITY ATOMS, MAKING THESE MATERIALS FUNDAMENTAL TO ELECTRONICS

DIODE

TWO-TERMINAL SEMICONDUCTOR DEVICE THAT ALLOWS CURRENT TO FLOW IN ONE DIRECTION WHILE BLOCKING IT IN THE OPPOSITE DIRECTION

PN JUNCTION

WHERE P-TYPE SEMICONDUCTOR AND N-TYPE SEMICONDUCTOR ARE JOINED TOGETHER

BIAS

REFERS TO THE USE OF A DC VOLTAGE TO ESTABLISH SPECIFIC OPERATING CONDITIONS FOR AN ELECTRONIC DEVICE

DEPLETION REGION

A REGION DEVOID OF FREE CHARGE CARRIERS WHERE ELECTRONS FROM THE N-TYPE REGION DIFFUSE INTO THE P-TYPE REGION AND RECOMBINE WITH HOLES

BUILT-IN ELECTRIC FIELD

ESTABLISHES A POTENTIAL BARRIER WHICH OPPOSES FURTHER MOVEMENT OF ELECTRONS AND HOLES

0.7V

SILICON’S BUILT-IN ELECTRIC FIELD

FORWARD BIAS

WHEN A POSITIVE VOLTAGE IS APPLIED TO THE P-SIDE AND NEGATIVE TO THE N-SIDE, THE POTENTIAL BARRIER IS REDUCED, ALLOWING CURRENT TO FLOW

REVERSE BIAS

WHEN THE VOLTAGE IS REVERSED, THE DEPLETION REGION WIDENS, BLOCKING CURRENT FLOW

BARRIER POTENTIAL

THE BUILDUP OF POSITIVE AND NEGATIVE IONS CREATES AN ELECTRIC FIELD THAT PREVENTS MORE ELECTRONS FROM CROSSING THE JUNCTION WHICH CREATES ___

0.3V

POTENTIAL BARRIER FOR GERMANIUM

FORWARD BIAS

CONDITION THAT ALLOWS CURRENT TO FLOW THROUGH A DIODE

REVERSE BIAS

CONDITION THAT PREVENTS CURRENT FLOW THROUGH THE DIODE

50V

BREAKDOWN VOLTAGE IS TYPICALLY GREATER THAN ___ FOR MOST RECTIFIER DIODES

RECTIFIERS

CONVERT AC VOLTAGE INTO DC VOLTAGE

RECTIFIERS

ESSENTIAL COMPONENTS IN ALL DC POWER SUPPLIES THAT OPERATE FROM AN AC VOLTAGE SOURCE

HALF-WAVE RECTIFIER

WHEN A DIODE IS CONNECTED TO AN AC SOURCE WHICH PROVIDES THE INPUT VOLTAGE AND LOAD TO A RESISTOR

PULSATING DC VOLTAGE

HAS A SIGNIFICANT RIPPLE, MAKING IT LESS SMOOTH COMPARED TO THE OUTPUT OF A FULL-WAVE RECTIFIER

DC VOLTMETER

THE AVERAGE VALUE OF A HALF-WAVE RECTIFIED OUTPUT VOLATGE IS THE VALUE YOU WOULD MEASURE ON A ____

FULL-WAVE RECTIFIER

CIRCUIT THAT CONVERTS AN ENTIRE AC WAVEFORM INTO A PULSATING DC VOLTAGE

CENTER-TAP FULL-WAVE RECTIFIER

TYPE OF FULL-WAVE RECTIFIER THAT IS BULKIER BUT EFFICIENT

BRIDGE RECTIFIER

TYPE OF FULL-WAVE RECTIFIER THAT IS MORE EFFICIENT AND WIDELY USED DUE TO ITS SIMPLER TRANSFORMER REQUIREMENT

CENTER-TAP FULL-WAVE RECTIFIER

TYPE OF RECTIFIER CIRCUIT THAT USES A CENTER-TAPPED TRANSFORMER AND TWO DIODES TO CONVERT AN ALTERNATING CURRENT INPUT INTO A PULSATING DIRECT CURRENT OUTPUT

TURNS RATIO

DETERMINES THE OUTUT VOLTAGE OF A FULL-WAVE RECTIFIER

PEAK INVERSE VOLTAGE

PIV

FULL-WAVE BRIDGE RECTIFIER

WIDELY USED CIRCUIT FOR CONVERTING AC TO DC

TRANSFORMER THEORY

THEORY WHERE THE SECONDARY VOLTAGE IS RELATED TO THE PRIMARY VOLTAGE BY THE TURNS RATIO OF THE TRANSFORMER

DC POWER SUPPLY

CIRCUIT THAT CONVERTS THE STANDARD 120V, 60Hz AC VOLTAGE AVAILABLE AT WALL OUTLETS INTO A CONSTANT DC VOLTAGE

RECTIFIER

HEART OF THE DC POWER SUPPLY

BLOCK DIAGRAMS

USED TO ILLUSTRATE THE BASIC OPERATION OF RECTIFIERS AND A REGULATED DC POWER SUPPLY

RECTIFIER

CONVERTS THE AC INPUT VOLTAGE INTO A PULSATING DC VOLTAGE

CAPACITOR FILTER

USED TO ELIMINATE THE FLUCTUATIONS IN THE REACTIFIED VOLTAGE

REGULATOR

CIRCUIT DESIGNED TO MAINTAIN A CONSTANT DC OUTPUT VOLTAGE, EVEN WHEN THERE ARE VARIATIONS IN THE INPUT LINE VOLTAGE OR CHANGES IN THE LOAD

LOAD

REPRESENTS THE CIRCUIT OR DEVICE THAT THE POWER SUPPLY IS DESIGNED TO POWER

RIPPLE VOLTAGE

FLUCTUATION IN OUTPUT VOLTAGE CAUSED BY THIS CHARGING AND DISCHARGING PROCESS

IC VOLTAGE REGULATOR

MINIMIZE RIPPLE AND MAINTAIN A STABLE OUTPUT VOLTAGE DESPITE INPUT FLUCTUATIONS

EXTERNAL CAPACITORS

USED FOR FILTERING, PREVENTING OSCILLATION, AND IMPROVING TRANSIENT RESPONSE, ENSURING RELIABLE POWER SUPPLY PERFORMANCE

LM317

ONE OF THE MOST POPULAR ADJUSTABLE REGULATORS