Basic Electronics Flashcards
1
Q
The atomic theory is largely credited to who?
A
John Dalton
2
Q
Diameter of typical Nucleus
A
1x10^-14
3
Q
Thomspon’s model of the atom
A
PLum pudding, (he discovered electron)
4
Q
Rutherford’s discovery of subatomic particle
A
Proton
5
Q
Chadwick’s discovery of subatomic particle
A
Neutron
6
Q
What consists of proton?
A
2 up quark
1 down quark
7
Q
Composition of neutron?
A
2 down quark
1 up quark
8
Q
formula of maximum number of electrons in a given shell, n
A
n=2n^2
9
Q
What letter does the first electron shell starts?
A
K
10
Q
What is Pauli’s Exclusion Principle
A
no two electrons can have the same set of four quantum numbers
11
Q
Equivalent of 1 eV in Joules
A
1.602x10^-19 J
12
Q
Group IV elemental semiconductors
A
Diamond (C)
Silicon(Si)
Germanium(Ge)
13
Q
The energy Required to move an electron from the valence band into the conduction band
A
energy gap (Eg)
14
Q
It is the bonding resulting from the attractive forces of oppositely charged ions
A
Ionic band
15
Q
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
A
Metallic bond
16
Q
It is when atoms of materials share electrons with another atoms
A
Covalent bond
17
Q
At absolute zero temperature, how many free electrons are found in a semiconductor?
A
Zero, because they are locked in their valence bond
18
Q
It refers to pure Semiconfuctors and free from impurities
A
Intrinsic materials
19
Q
Semiconductors that are doped with impurities
A
Extrinsic Materials
20
Q
it is the process of adding impurities
A
doping
21
Q
Common pentavalent(N-Type) materials
A
Antimony(Sb) Arsenic(As) Phosphorus(P)
22
Q
Common trivalent(P- Type) elements
A
Boron(B) Gallium (Ga) and Indium (I)
23
Q
The difference on the effect of lightly and heavily doping a semiconductor
A
lightly doped - few impurities, higher resistance
heavily doped - more impurities, lower resistance
24
Q
What is the depletion region?
A
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
