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Flashcards in Basic Electronics Deck (173):
1

The atomic theory is largely credited to who?

John Dalton

2

Diameter of typical Nucleus

1x10^-14

3

Thomspon's model of the atom

PLum pudding, (he discovered electron)

4

Rutherford's discovery of subatomic particle

Proton

5

Chadwick's discovery of subatomic particle

Neutron

6

What consists of proton?

2 up quark
1 down quark

7

Composition of neutron?

2 down quark
1 up quark

8

formula of maximum number of electrons in a given shell, n

n=2n^2

9

What letter does the first electron shell starts?

K

10

What is Pauli's Exclusion Principle

no two electrons can have the same set of four quantum numbers

11

Equivalent of 1 eV in Joules

1.602x10^-19 J

12

Group IV elemental semiconductors

Diamond (C)
Silicon(Si)
Germanium(Ge)

13

The energy Required to move an electron from the valence band into the conduction band

energy gap (Eg)

14

It is the bonding resulting from the attractive forces of oppositely charged ions

Ionic band

15

It is the product of the attractive forces of group of positive ions and electrons, where the electrons are generally free to move about its ions

Metallic bond

16

It is when atoms of materials share electrons with another atoms

Covalent bond

17

At absolute zero temperature, how many free electrons are found in a semiconductor?

Zero, because they are locked in their valence bond

18

It refers to pure Semiconfuctors and free from impurities

Intrinsic materials

19

Semiconductors that are doped with impurities

Extrinsic Materials

20

it is the process of adding impurities

doping

21

Common pentavalent(N-Type) materials

Antimony(Sb) Arsenic(As) Phosphorus(P)

22

Common trivalent(P- Type) elements

Boron(B) Gallium (Ga) and Indium (I)

23

The difference on the effect of lightly and heavily doping a semiconductor

lightly doped - few impurities, higher resistance
heavily doped - more impurities, lower resistance

24

What is the depletion region?

no electrons or holes

25

It is the simplest diode

point contact germanium diode

26

It is where anode is more positive than the anode nd where the diode allow current to flow

Forward bias

27

It is the maximum voltage that can be applied that can be handled by the junction diode

Breakdown voltage
*note that silicon has higher breakdown voltage than germanium

28

Diode forward current equation

Id = Is*(e^(kVd/Tk) - 1)

Id = diode current
Is = reverse saturation current/Leakage current
Vd = forward diode voltage
Tk = room temp, in Kelvin
k = 11,600/n
n = 1 for Ge , 2 for Si (1 by default)

29

Formula for Effect of temperature on reverse saturation current

I(snew) = I(s)·e^k(T1 - T0)

I(snew) =reverse saturation current at new temperature
I(s) =reverse saturation current at room
k = 0.07
T1 = new temperature
T0 = room temperature

30

Formula for Effect of temperature on threshold voltage

Vth1 = Vth + k*(T1 - T0)

Vth1 = threshold voltage at new temperature
Vth = threshold voltage at room temperature ( 0.3 V for Ge and 0.7 V for Si)
k = -2.5 mV/C for Ge = -2.0 mV/C for Si
T1 = new temperature
T0 = room temperature

31

Three Diode Equivalent Models

Ideal Diode Model
Simplified Diode Model
Piecewise Linear Diode Model

32

A diode model with no threshold voltage required and has no resistance when forward biased

Ideal Diode Model

33

A diode model when forward biased has threshold voltage and has no resistance

Simplified Diode Model

34

A diode model when forward biased has threshold voltage and resistance

Piecewise Linear Diode Model

35

Threshold Voltage for Silicon

0.7 V

36

Threshold Voltage for Germanium

0.3 V

37

The forward resistance of the diode under DC circuit analysis

Static Resistance

38

Formula for Static Resistance

Rd = DC voltage across the diode / Diode's current
Rd = Vd / Id

39

The forward resistance of the diode under AC circuit Analysis

Dynamic Resistance

40

Formula for Dynamic Resistance

rd = small change of voltage / small change of diode's current
rd = dVd / dId
rd = 26 mV / Id

41

The forward resistance of the diode under AC circuit analysis

Average AC Resistance

42

Formula for Average AC Resistance

r(ave) = Change in voltage across the diode / Change in diode's current
r(ave) = Δ Vd / Δ Id

43

Capacitance prominent when diode is Forward-biased:

The diffusion / storage capacitance

44

Capacitance prominent when diode is Reverse-biased:

The transition / depletion-region capacitance

45

At lower frequency the diode(due to capacitance) acts like a ___________

Open circuit

46

At high frequency the diode(due to capacitance) acts like a ___________

Short Circuit

47

The magnitude of current that the diode can handle without burning when forward biased

Forward Current

48

This is the required voltage in order to produce forward current

Forward Voltage

49

The magnitude of current that will leak when the diode is reverse-biased

Reverse Saturation current

50

Other term for Reverse Saturation current

Leakage Current

51

This is the maximum reverse voltage that can be applied before current surge and enters the Zener region

Reverse Breakdown Voltage
Peak Reverse Voltage
Peak Inverse Voltage

52

This is the time taken by the diode to operate from forward conduction to reverse bias condition

Reverse Recovery Time

53

The maximum power the diode can handle without burning

Maximum Power Dissipation

54

The factor that tells the reduction of power handling capability of the diode due to the increase of ambient temperature from room temperature

Linear Power Derating Factor

55

The maximum temperature the diode can operate before burning its junction

Maximum Junction Temperature

56

Formula for Reverse Recovery Time

T(rr) = t(s) + t(t)

T(rr) = the time elapsed from forward to reverse bias
t(s) = the transition time
t(t) = the storage time

57

Analogous to the junction diode except that the doping is controlled precisely so that it will have a well defined and smaller breakdown voltage

Zener Diode

58

The Zener effect was discovered by

Dr. Clarence Melvin Zener

59

Formula for Temperature Coefficient (measures ΔVz ad temperature changes)

Tc = ΔVz / Vz (T1 - T0) x 100%

ΔVz = Resulting Change in Zener Potential
Vz = The Zener Diode Breakdown Voltage
T1 = new temperature
T0 = room temperature

60

A Variable Capacitor, Commonly used in parametric amplifiers, parametric oscillators and voltage-controlled oscillators as part of phase-locked loops and frequency synthesizers

Varactors

61

Varactors are usually operated in what bias

Reverse-Biased

62

It is the sum of the junction and case capacitances

Total diode capacitance

63

It is the resistance in series with the junction of the diode

Series resistance

64

Formula for Quality Factor of a varactor

Q = 0.159 / (f·R(s)·C(t))

f = frequency in Hertz
R(s) = series resistance in ohms
C(t) = total capacitance in farad

65

It is the frequency where the quality factor of the varactor is 1

Cutoff frequency

66

It is the ratio of capacitance variation at a reverse voltage of -4 or -6 to the capacitance at approximately 80 percent of the breakdown voltage

Total Capacitance Ratio

67

It is defined as the performance of a varactor used as a frequency multiplier

Conversion efficiency(varactor)

68

Formula for Conversion efficiency(of a varactor)

η = Po / Pi x 100%

69

Relation of temperature to capacitance

directly proportional

70

Diodes usually made of doped silicon or germanium

Generic Diode

71

Type of diode that is made to conduct backwards

Zener Diode

72

Conduct in the reverse direction when the reverse bias voltage exceeds the breakdown voltage

Avalanche diode

73

Occurs when the reverse electric field across the pn junction causes a wave of ionization

Avalanche effect

74

Reverse Breakdown of avalanche diode

6.2 V

75

Are avalanche diodes designed specifically to protect other semiconductor devices from electrostatic discharges

Transient voltage suppression diode (TVS)

76

Type of diode that subject to optical charge carrier generation and therefore most are packaged om light blocking material.

Photodiodes

77

Type of diode that formed in a direct band-gap semiconductor, such as gallium arsenide, carriers that cross the junction emit photons when they recombine with majority carrier on the other side

Light Emitting Diode (LED)

78

Forward potential of Red LED and Violet LED

1.2 V and 2.4 V

79

What is the first LEDs created

Red and Yellow

80

An LED-like structure is contained in a resonant cavity formed by polishing the parallel end faces

Laser Diode

81

A Diode that have a lower forward voltage drop than a normal PN junction, because they are constructed from a metal to semiconductor contact.

Schottky Diode

82

is a semiconductor junction diode having the ability to generate extremely short pulses (Low Reverse Recovery Time).

step recovery/snap-off diode

83

a two-terminal semiconductor diode using tunneling electrons to perform high-speed switching operations

Esaki or tunnel diode

84

Similar to tunnel diode that exhibit a region of negative differential resistance and is used in Microwave Frequency Oscillation

Gunn diodes

85

A block of n-type semiconductor is built, and a conducting sharp-point contact made with some group-3 metal is placed in contact with the semiconductor.

Point Contact Diode

86

They are used as voltage-controlled capacitors

Varicap

87

A diode with similar to JFET which allow a current through them to rise to a certain value

Current-limiting field-effect diodes

88

Some diode applications

Radio Demodulation
Power Conversion
Over-voltage Protection
Logic Gates
Ionizing Radiation Detectors
Temperature measuring
Charge coupled devices

89

It is a three terminal current controlled solid state device which is capable of amplifying signals

Transistor

90

Who invented the transistor?

John Dalton and Walter Brattain
Bell Laboratories
1947

91

What are the first type of transistor?

Point-Contact Type

92

The theorist who was leading the research about point-contact type transistor

William Shockley

93

The main conduction channel employs both electrons and holes to carry the main electric current.

Bipolar Junction Transistor (BJT)

94

Three parts of the transistors

Emitter, Base and Collector

95

Two basic modes of transistor

Switch and Amplifier

96

When the Base-Emitter is Forward and Base-Collector is Reverse, The operating mode is

Active or Amplifier

97

When the Base-Emitter is Forward and Base-Collector is Forward, The operating mode is

Saturation ( On Mode )

98

When the Base-Emitter is Reverse and Base-Collector is Reverse, The operating mode is

Cut-off ( Off Mode )

99

Current Relationships of TBJT

IE = IB + IC + ICBO
ICBO ≈ 0 (neglible)

100

It is the common base amplification factor

α (alpha)

101

Formula for α (alpha)

α = IC / IE

102

It is the common emitter forward current amplification factor

β (beta)

103

Formula for β ( beta)

β = IC / IB

104

It is the common collector forward current amplification factor

γ = IE / IC

105

Parameter Relationship for α, β and γ

α = β / β + 1
β = α / α - 1
γ = 1 + β

106

It is used for impedance matching application especially for low to high impedance conversion

Common Base Configuration

107

It is most used configuration for amplifier application

Common Emitter Configuration

108

It is also used for impedance matching application especially for high to low impedance conversion

Common Collector Configuration

109

A process of applying a DC voltage to a transistor to achieve the preferred region of operation or for what application is the transistor intended

Biasing

110

Type of biasing which has the greatest power gain but the most unstable type of biasing.

Fixed Bias

111

Type of biasing which is considered the most stable of all the biasing configurations but requires more resistors than any other biasing

Voltage divider bias configuration

112

Type of biasing which is more stable than fixed-bias but with a smaller power gain

Emitter-stabilized bias configuration

113

Type of biasing which has the advantage of requiring fewer resistors compared to voltage divider bias without reducing the stability

Voltage feedback bias configuration

114

Two main criteria considered in choosing which bias configuration is to be used

Power gain
Stability

115

When temperature increases, the β ______________
When temperature increases, the Vbe ____________
When temperature increases, the Ico __________

increases
increases
increases

116

Formula for stability factors

S(Ico) = ∆Ic / ∆Io
S(Vbe) = ∆Ic / ∆Vbe
S(β) = ∆Ic / ∆β

117

Formula for Total Change of Collector Current

∆Ic = S(Ico) ∆Ico + S(Vbe) ∆Vbe + S(β)∆β

118

The most commonly used model in small signal analysis of transistors

Hybrid Parameter Model

119

Equations for H-Parameter

Vi = hi⋅Ii + hr⋅Vo
Io = hf⋅Ii + ho⋅Vo

120

Formula of a re model

re = 26 mV / IE

121

Comparison between H-parameter and Re model

For input impedance or resistance
re ≈ h(ib)
βre≈h(ie)≈h(ic)
For amplication factor
α≈h(fb)
β≈h(fe)≈h(fc)

122

Parameter for Common Base

Input impedance - Low
Output Impedance - High
Current Gain - Low ≈ 1
Voltage Gain - High
Power Gain - Moderate
Phase shift - None

123

Parameter for Common Emitter

Input impedance - Moderate
Output Impedance - Moderate
Current Gain - Moderate
Voltage Gain - Moderate
Power Gain - High
Phase shift - 180°

124

Parameter for Common Collector

Input impedance - High
Output Impedance - Low
Current Gain - High
Voltage Gain - Low ≈ 1
Power Gain - Low
Phase shift - None

125

Transistor model know as the transistor physical representation

T-equivalent circuit

126

Transistor model used in DC analysis

Ebers-Moll model

127

Transistor model used in small signal analysis

Hybrid model

128

Transistor model used in high frequency analysis

Hybrid-pi model or Giacolleto model

129

Transistor model used small signal and large signal analysis

Dynamic or re model

130

Is a transistor that uses an electric field to control the electrical behavior of the device.

Field-Effect Transistor

131

Different types of field-effect transistor

JFET ( Junction Field-Effect Transistor )
MOSFET ( Metal-Oxide-Semiconductor Field-Effect Transistor )
MESFET ( Metal-Semiconductor Field-Effect Transistor )
HEMT ( High Electron Mobility Transistor )

132

Is a unipolar device that is either only electron or hole is the charged carrier but not both

JFET ( Junction Field-Effect Transistor )

133

Is an electronic amplifying vacuum tube (or valve in British English) consisting of three electrodes inside an evacuated glass envelope

Triode

134

Formula for Drain current for FET

i(d) = I(DSS) ( 1 - (VGS / VP))^2
i(d) = Drain current
I(DSS) = Drain to Source Current Saturate
VGS = Gate to Source Voltage
VP = Pinch Off Voltage

135

It is constructed by placing an insulting layer between the gate and the channel allows for a wider range of control voltages and further decreases the gate current

MOSFET ( Metal-Oxide-Semiconductor Field-Effect Transistor )

136

Type of MOSFET which has a channel in resting state that gets snakker as a reverse bias is applied, this device conducts current with no bias applied

D-MOSFET ( Depletion Metal-Oxide-Semiconductor Field-Effect Transistor )

137

Type of MOSFET which is built without a channel and does not conduct current when Vgs = 0

E-MOSFET ( Enhancement Metal-Oxide-Semiconductor Field-Effect Transistor )

138

Type of FET which quite similar to a JFET in construction and terminology. The difference is that Schottky junction is used.

MESFET ( Metal-Semiconductor Field-Effect Transistor )

139

It is a FET with a junction between two materials with different band gaps as the channel instead of an n-doped region

HEMT ( High Electron Mobility Transistor )

140

Conductors ideally have _____ valence electrons

1

141

Valence electron count of a conductor

Less than four

142

Group in Periodic table attributed with properties that make them conductors

Group 1B
(Cu, Ag, Au)

143

Insulators ideally have _____ valence electrons

8

144

Valence electron count of an insulator

More than four

145

A Semiconductor has _______ valence electrons

4

146

Semiconductors act like _________ at 0°K

Insulator

147

Insulators have energy gaps above

5 eV

148

With a conductor, its valence band _______ the conduction band

Overlaps
(∴ Eg Conductor = 0 eV)

149

The distance of the electron from the nucleus is ________ proportional to the energy gap required for electron to move to conduction band

Inversely Proportional
(∴ As atomic number decreases, energy gap increases)

150

Energy Gap of Silicon

1.1 eV

151

Energy Gap of Germanium

0.67 eV

152

Energy Gap of Gallium Arsenide

1.43

153

Energy Gap of Gallium Phosphide

2.26

154

At 0°K, there are ______ free electrons in a semiconductor

zero

155

The number of free electrons in 1 cm³ of Silicon

1.5 x 10^10 electrons

156

The number of free electrons in 1 cm³ of Germanium

2.5 x 10^15 electrons

157

At room temperature, Silicon is _________

Insulative

158

At room temperature, The Thermal energy will only produce ______ free electrons in a material

few

159

A Doped Semiconductor that are doped with Trivalent Impurities

P-Type Semiconductor

160

A Doped Semiconductor that are doped with Pentavalent Impurities

N-Type Semiconductor

161

Another term for Trivalent atoms

Acceptor atoms
(3 Valence electrons; to become four Valence semiconductor, atom must ACCEPT an electron)

162

Another term for Pentavalent atoms

Donor atoms
(5 Valence electrons; to become four Valence semiconductor, atom must DONATE an electron)

163

P-Type Semiconductors have _______ as Majority Carriers, and _________ as Minority Carrier

Holes as Majority Carriers (P-Type, POSITIVE)
Electrons as Minority Carriers

164

N-Type Semiconductors have _______ as Majority Carriers, and _________ as Minority Carrier

Electrons as Majority Carriers (N-Type, NEGATIVE)
Holes as Minority Carriers

165

Net Charge INSIDE The depletion region of a PN Junction is _____

Zero

166

In Forward Bias Condition, The Depletion Region ______

Narrows

167

In Reverse Bias Condition, The Depletion Region ______

Widens

168

Alternative Forward Current (Id) Equation

Id = Is*( [e^(Vd / (n*Vt)] - 1)

Vt - Thermal Voltage (26mV @ 300°K)
Vd - Forward Diode Current
Is - Reverse Saturation/Leakage Current
n - 1 by default

169

Formula for Thermal Voltage (Vt)

Vt = k*T / qe

k - Boltzmann's Constant
T - Temperature(in °K)
qe - Electron Charge (1.6 x 10^-19 C)

170

The Storage/Diffusion Capacitance is the _______ of the diode

Maximum
(C =Ea/d, DR acts as dielectric, and since DR is thin at forward bias, Capacitance increases)

171

The Transition/Depletion-Region Capacitance is the _________ of the diode

Minimum
(C =Ea/d, DR acts as dielectric, and since DR is thick at reverse bias, Capacitance decreases)

172

Why does a PN Junction diode have capacitance in the first place?

DR acts like a Dielectric(any non-conductor) between two plates (P-Type and N-Type Material act like plates)

173

Reverse Recovery Time ranges from _____ to ____

few nanoseconds to few hundred picoseconds