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Bryx_Electronics > Amplifiers and Feedback > Flashcards

Amplifiers and Feedback Flashcards

1
Q

Device that accepts a varying input signal and produces a larger version of it at the output

A

Amplifier

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2
Q

Voltage Gain

A

Vout / Vin

in dB:

20 log (Vo/Vi)

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3
Q

Power Gain

A

Po / Pi

in dB:

10 log (Po/Pi)

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4
Q

Gain in Cascade

A

A1 x A2 x A3 . . .

in dB:

A1 + A2 + A3 . . .

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5
Q

Device that amplifies input signal voltage

A

Voltage Amplifier

Duh!

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6
Q

Device that amplifies input signal Power

A

Power Amplifier

What did you expect?

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7
Q

Designed to amplify frequencies between 15 Hz to 20 kHz

A

Audio Amplifier

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8
Q

Designed to amplify frequencies between 10 kHz to 100,000 MHz

A

Radio Frequency Amplifier (RF)

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9
Q

Designed to amplify frequencies between 10 Hz to 6 MHz

A

Video Amplifier (also called Wide-band Amplifier)

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10
Q

Amplifier where current in the output flows for the entire cycle (360 deg)

It has good fidelity but low efficiency

A

Class A Amplifier

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11
Q

Amplifier where current in the output flows for 51% -
99% of the cycle (180< O < 360)

It has poor fidelity but high efficiency

A

Class AB Amplifier

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12
Q

Amplifier where current in the output flows for 50% of the cycle (180 deg)

A

Class B Amplifier

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13
Q

Amplifier where current in the output flows for part of 50% of the cycle

It has worst fidelity but highest efficiency

A

Class C Amplifier

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14
Q

Device that generates AC from DC input

A

Oscillator

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15
Q

LC Oscillator with Tapped Inductor

A

Hartley Oscillator

*H…Hinductor pwede din H for Henry. Your choice.

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16
Q

LC Oscillator with Tapped Capacitor across an Inductor

A

Colpitts Oscillator

*C… opposite L pitts

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17
Q

LC Oscillator with Tapped Capacitor across a Inductor-Capacitor series combination

A

Clapp Oscillator

*C…L…app

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18
Q

Formula for Gain without Feedback (Aol) and Feedback Factor (β) for Hartley Oscillattor

A 
Aol = Lo/Li
β = Li/Lo
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19
Q

Formula for Gain without Feedback (Aol) and Feedback Factor (β) for Colpitts Oscillators

A 
Aol = Ci/Co
β = Co/Ci
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20
Q

Crystal oscillator provides very stable oscillation. The frequency drift of crystal oscillator is only

A

0.0001% or 1 ppm

Secret Info:
LC oscillators have 0.8% frequency drift (Shhhh)

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21
Q

Crystal with greatest piezoelectric activity, the most unstable oscillator

A

Rochelle Salt

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22
Q

Crystal with least piezoelectric activity, the toughest, and the most expensive, therefore the most stable oscillator,

A

Tourmaline

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23
Q

Crystal material that have midway properties between Rochelle and Tourmaline, and is the cheapest among the three crystal materials

A

Quartz

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24
Q

The Resonant Frequency of a piezoelectric crystal is __________ proportional to its thickness

A

Inversely proportional

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25
Q

Formula for The Open-loop Gain(Aol) and Feedback factor(β) of RC Phase-Shift Oscillator

A 
Aol = -Rf / Rs (Inverting Op-Amp)
Aol = -29 (required value in Phase Shift Oscillator)

So, if β*Aol must be equal to 1:
β = -1/29

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26
Q

Formula for The Open-loop Gain(Aol) and Feedback factor(β) of RC Wein bridge Oscillator

A 
Aol = 1 + (Rf / Rs) (Non - Inverting Op-Amp)
Aol = 3 (required value in Wein Bridge Oscillator)

So, if β*Aol must be equal to 1:
β = 1 / 3

Rf / Rs must be equal to 2

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27
Q

Types of Sampling in a Negative Feedback Amplifier Circuit

A 
Voltage Sampling (Shunt)
Current Sampling (Series)
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28
Q

Types of Mixing in a Negative Feedback Amplifier Circuit input

A 
Series Mixing (Voltage additive)
Shunt Mixing (Current series)
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29
Q

Formula for Voltage Gain with feedback (Af)

A

Af = A / (1 + BA)

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30
Q

Types of Feedback Connection

A

Voltage-Series
Current-Series
Voltage-Shunt
Current-Shunt

  • First part describes the output part of the amplifier
  • Second part describes the input part of the amplifier
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31
Q

Gains and Feedback Factor in Voltage-Series Feedback Connection

Input and Output impedance

A 
A = Vo / Vi
B = Vf / Vo
Af = Vo / Vs

Afv = A / (1 + BA)

Zin = Zi(1 + BA)
Zout = Zo / (1 + BA)
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32
Q

Gains and Feedback Factor in Current-Series Feedback Connection

Input and Output impedance

A 
G = Io / Vi
B = Vf / Io
Af = Io / Vs

Afv = G / (1 + BG)

Zin = Zi(1 + BG)
Zout = Zo(1 + BG)
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33
Q

Gains and Feedback Factor in Voltage-Shunt Feedback Connection

Input and Output impedance

A 
R = Vo / Ii
B = If / Vo
Af = Vo / Is

Afv = R / (1 + BR)

Zin = Zi / (1 + BR)
Zout = Zo / (1 + BR)
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34
Q

Gains and Feedback Factor in Current-Shunt Feedback Connection

Input and Output impedance

A 
A = Io / Ii
B = If / Io
Af = Io / Is

Afv = A / (1 + BA)

Zin = Zi / (1 + BA)
Zout = Zo(1 + BA)
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35
Q

Gain Margin (Formula)

A

GM = 1 / β*Aol

in dB:

GM = - 20log(β*Aol)

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36
Q

An OSCILLATOR employs _______ Feedback

A

pOSItive Feedback

“pOSItive, OSCIllator”

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37
Q

Formula for Feedback Gain(Af) of a Positive Feedback Oscillator

A

Af = A / ( 1 - βA)

A - Open Loop Gain / Gain Without Feedback
β - Feedback Element Gain (Less than or equal to 1)

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38
Q

What βA is required in a Positive Feedback Oscillator so that the Oscillator self-oscillates

A

βA must be equal to 1
Af = A / ( 1 - 1)
Af = A / 0
Af = ∞

This means that even just noise as an input will start oscillating the Positive Feedback Oscillator (Self-Oscillator)

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39
Q

Barkhausen Criterion

there are 2

A

1.) The Net Gain |βA| is equal to 1

2.) The NET Phase shift of the feedback loop must be an integer multiple of 360°
(SO that feedback signal is in phase with the input to the oscillator to enable positive feedback)

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40
Q

A Positive Feedback Oscillator usually has a circuit called a _________

A

Tank Circuit

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41
Q

The principle of oscillation the tank circuit employs

A

Flywheel Effect

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42
Q

The reason why the Flywheel effect dampens is due to the ________

A

Resistance in the coil of the inductor

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43
Q

To decrease the Damping effect of the coil resistance in the inductor, the __________ must be increased

A

Quality factor

Q = XL / Rcoil

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44
Q

The output of a Harmonic Oscillator is _____

A

Sinusoidal

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45
Q

The output of a Relaxation Oscillator is _____

A

Digital

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46
Q

In Positive Feedback, the Feedback Signal must be ______ with the incoming input signal

A

In Phase

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47
Q

Another term for ‘ Q ‘

A

Figure of Merit

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48
Q

Two types of RC Positive Feedback Oscillators

A
  • Phase Shift Oscillators

- Wein Bridge Oscillators

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49
Q

A Phase Shift Oscillator’s passive network consists of ____ Lead (and/or) ____ Lag Circuits

A

3 Lead Circuits
OR
3 Lag Circuits

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50
Q

The Passive network of a Phase Shift Oscillator must provide a total of ______° Phase Shift (____° for each lead/lag circuit used)

A

180° Phase Shift (60° Phase shift per lead/lag circuit)

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51
Q

A Phase Shift Oscillator’s OP-Amp configuration is in a/an ____________

A

Inverting Amplifier

Aol = -Rf / Rs

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52
Q

Formua for The Resonant Frequency(fr) of a Phase Shift Oscillator

A

fr = 1 / ( 2πRC*√6 )

R - resistor used in the passive Lead/Lag Network
C - capacitor used in the passive Lead/Lag Network

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53
Q

A Wein Bridge Oscillator’s passive network consists of ____ Lead (and/or) ____ Lag Circuits

A

1 Lead Circuit AND 1 Lag Circuit

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54
Q

A Wein Bridge Oscillator’s OP-Amp configuration is in a/an ____________

A

Non - Inverting Amplifier

Aol = 1 + (Rf / Rs)

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55
Q

Formua for The Resonant Frequency(fr) of a Wein Bridge Oscillator

A

fr = 1 / ( 2π√[RleadCleadRlagClag] )

Rlead/Rlag - resistor used in the passive Lead/Lag Network
Clead/Clag - capacitor used in the passive Lead/Lag Network

If Rlead = Rlag = R, and Clead = Clag = C

fr = 1 / ( 2π*√[RC] )

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56
Q

Four common LC Positive Feedback Oscillators

A
  • Hartley Oscillator
  • Colpitts Oscillator
  • Clapp Oscillator
  • Armstrong Oscillator
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57
Q

A Hartley Oscillator’s feedback circuit consists of: _____

A

(Capacitor) in parallel to (two inductors(Li, Lo), with ground tapped between them)

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58
Q

A Colpitts Oscillator’s feedback circuit consists of: ______

A

(Inductor) in parallel to (two Capacitors(Ci, Co), with ground tapped between them)

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59
Q

A Clapp Oscillator’s feedback circuit consists of: ______

A

(A capacitor in series to an inductor{CLapp}) in parallel to (two Capacitors(Ci, Co), with ground tapped between them)

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60
Q

An Armstrong Oscillator uses a __________, a component not present in the other three LC Oscillators

A

Transformer

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61
Q

Formula for Resonant Frequency of a Hartley Oscillator

A

fr = 1 / { 2π√(LeqC) }

Leq = Li +Lo +2M
M = k√(LiLo)
k - coupling factor (1 by default/not specified)

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62
Q

Formula for Resonant Frequency of a Colpitts Oscillator

A

fr = 1 / { 2π√(LCeq) }

Ceq = (Ci*Co / (Ci + Co))

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63
Q

Formula for Resonant Frequency of a Clapp Oscillator

A

fr = 1 / { 2π√(LCeq) }

Ceq = 1 / { (1/Ci) + (1/Co) + (1/C) }

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64
Q

Formula for Resonant Frequency of an Armstrong Oscillator

A

fr = 1 / 2π√(LpriC)

Lpri - Inductance of the primary coil of the transformer

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65
Q

Effective Crystal lumped sum circuit

A 
1st Branch: L (series) Cs (series) R
2nd Branch(parallel to 1st branch): Miller Capacitance (Cm)
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66
Q

Formula for Crystal oscillator series resonant frequency

A

frs = 1 / 2π√(LCs)

Cs - Capacitance in series with the stray conductance in a crystal oscillator

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67
Q

When a Crystal Oscillator is operating at the Series Resonant Frequency, its impedance is __________

A

Z = 0 Ω

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68
Q

The Series Resonant Frequency is (> , < , = ) the Parallel Resonant Frequency of the Crystal Oscillator

A

Less than

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69
Q

Formula for Crystal oscillator series resonant frequency

A

frs = 1 / 2π√(L * [CsCm / (Cs + Cm)] )

Cs - Capacitance in series with the stray conductance in a crystal oscillator
Cm - Miller Capacitance in parallel to the Crystal Oscillator

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70
Q

When a Crystal Oscillator is operating at the Parallel Resonant Frequency, its impedance is __________

A

Z = ∞ Ω

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71
Q

The most stable Positive Feedback Oscillator

A

Pierce Crystal Oscillator

AKA Crystal Controlled Oscillator

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72
Q

With a Pierce Crystal Oscillator, a Crystal replaces the ______ in a Colpitts Oscillator

A

Inductor

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73
Q

Due to the Lumped Circuit of the Crystal, the whole oscillator setup will look like a ______ Oscillator

A

Clapp:

(Lcrystal in series with Ccrystal) || (Two capacitors)

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74
Q

Another Term for Relaxation Oscillator

A

Multivibrator ( ͡° ͜ʖ ͡°)

75
Q

A Multivibrator ( ͡° ͜ʖ ͡°) uses ___ Amplifiers and ____ Passive Networks

A

Two Amplifiers (only one is “turned on”( ͡° ͜ʖ ͡°) at any given time) and two Passive Networks

76
Q

A Multivibrator ( ͡° ͜ʖ ͡°) employs ______ Feedback

A

positive

77
Q

When the two passive networks of a multivibrator ( ͡° ͜ʖ ͡°) are both Resistors, the Multivibrator ( ͡° ͜ʖ ͡°) is considered as operating in ________ mode

A

Bistable

78
Q

When the two passive networks of a multivibrator ( ͡° ͜ʖ ͡°) are both Capacitors, the Multivibrator ( ͡° ͜ʖ ͡°) is considered as operating in ________ mode

A

Astable

79
Q

When one passive network of a multivibrator ( ͡° ͜ʖ ͡°) is a Resistor, and the other is a capacitor, the Multivibrator ( ͡° ͜ʖ ͡°) is considered as operating in ________ mode

A

Monostable

80
Q

Multivibrators ( ͡° ͜ʖ ͡°) are either _______ or _______ when it comes to triggering

A

Self-Excited or Driven

81
Q

The State of the Multivibrator ( ͡° ͜ʖ ͡°) that does not change unless circuit is disturbed

A

Stable

82
Q

The State of the Multivibrator ( ͡° ͜ʖ ͡°) That remains unchanged, only for a certain amount of time

A

Quasi-Stable

83
Q

A Bistable Multivibrator ( ͡° ͜ʖ ͡°) is also known as a _________, and has _____ Stable states and ______ Quasi-Stable States

A
  • Flip-Flop, Binary, or Eccless-Jordan Multivibrator ( ͡° ͜ʖ ͡°)
  • 2 Stable States, 0 Quasi-Stable States
84
Q

A Monostable Multivibrator ( ͡° ͜ʖ ͡°) is also known as a _________, and has _____ Stable states and ______ Quasi-Stable States

A
  • One-Shot or Single-shot

- 1 Stable States, 1 Quasi-Stable States

85
Q

An Astable Multivibrator ( ͡° ͜ʖ ͡°) is also known as a _________, and has _____ Stable states and ______ Quasi-Stable States

A
  • Free-Running

- 0 Stable States, 2 Quasi-Stable States

86
Q

Negative Feedback Amplifiers are proposed by ________

A

Harold Black (1937)

87
Q

Another term for negative feedback

A

degenerative feedback

88
Q

Negative feedback setup are used for _________

A

Purely resistive amplifier networks

89
Q

Advantages of Negative Feedback over Positive Feedback

A
  • More Stable Voltage Gain
  • Wider BW
  • Lower Noise
  • More Linear Operation
90
Q

For a Negative Feedback, the feedback signal is _______ with respect to the incoming input signal

A

Out of Phase

91
Q

Formula for Feedback Gain(Af) of a Negative Feedback Oscillator

A

Af = A / ( 1 + βA)

A - Open Loop Gain / Gain Without Feedback
β - Feedback Element Gain (Less than or equal to 1)

92
Q

For the Negative Feedback Gain Formula ( Af = A / ( 1 + βA) ), The factor (1 + βA) is called the _______

A

Sacrifice Factor/Desensitivity Factor

93
Q

A [Voltage - {either series or shunt}] Feedback circuit has a ________

A

Low output Impedance (Zo)

(Voltage is sampled @ the output in parallel, and we all know that when a circuit is paralleled by anything, impedance goes down)

94
Q

A [Current - {either series or shunt}] Feedback circuit has a ________

A

High output Impedance (Zo)

(Current is sampled @ the output in Series, and we all know that when a circuit is Series’d by anything, impedance goes up)

95
Q

A [{either Voltage or Current} - Series] Feedback circuit has a ________

A

High input Impedance (Zi)

(Feedback signal is mixed @ the input in series, and we all know that when a circuit is Series’d by anything, impedance goes up)

96
Q

A [{either Voltage or Current} - Shunt] Feedback circuit has a ________

A

Low input Impedance (Zi)

(Feedback signal is mixed @ the input in parallel, and we all know that when a circuit is paralleled by anything, impedance goes down)

97
Q

For Negative Feedback setup, Mixing occurs at the (input/output)

A

Input

98
Q

For Negative Feedback setup, Sampling occurs at the (input/output)

A

Output

99
Q

General Zi or Zo (Zio) formula of a Negative Feedback Amplifier (My own version)

A

Ziₒᵣo = Ziₒᵣo(original) * ( 1 + βA)^k

Zio(original) - Zi or Zo of amplifier without feedback

k is -1 when we know that impedance goes down (depending on the setup)
k is +1 when we know that impedance goes up
(depending on the setup)

100
Q

For Voltage-Series Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)

A

Input: Voltage
Output: Voltage

101
Q

For Voltage-Shunt Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)

A

Input: Current
Output: Voltage

102
Q

For Current-Series Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)

A

Input: Voltage
Output: Current

103
Q

For Current-Shunt Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)

A

Input: Current
Output: Current

104
Q

Based on the input and output signal of a negative feedback amplifier, we can determine what the four setups amplify (also, state the open loop gain(Aol) of each):

A

Voltage Amplifier - Aol = Vo/Vi =Av
(belongs to Voltage Series)

Transresistance Amplifier - resistance is V / I
Aol = Vo / Ii = Rm
( belongs to Voltage - Shunt )

Transconductance Amplifier - conductance is I / V
Aol = Io / Vi =Gm
( belongs to Current - Series )

Current Amplifier - Aol = Io/Ii =Ai
(belongs to Current - Shunt)

105
Q

The Betas (β) of the four Negative Feedback Amplifiers

A

Voltage - Series: β = Vfeed / Vo

Voltage - Shunt: β = Ifeed / Vo

Current - Series: β = Vfeed / Io

Current - Shunt: β = Ifeed / Io

106
Q

The Closed loop gain (total gain w/ feedback (Af)) of the four negative feedback amplifiers

A

General form:

Af = Aol / (1 + β*Aol)

Aol = Av (if Voltage Series)
Aol = Rm (if Voltage Shunt)
Aol = Gm (if Current Series)
Aol = Ai (if Current Shunt)
107
Q

If β*Aol is muchmuch greater than 1, the estimate formula for the total gain w/ feedback(Af) is equal to:

A

Af = 1 / β

108
Q

The total gain w/ feedback(Af) is uninfluenced by the parameters of the __________

A

Amplifiers (Parameters like β, α, and γ for transistors)

109
Q

The best amplifier to be used among the four Negative Feedback Amplifiers is the _________

A

Voltage Series Amplifier

High Zi, Low Zo are the properties of an ideal OP amp

110
Q

A diagram that plots, for a given frequency, the gain response of a negative feedback amplifier, versus the phase shift if the signal at that gain

A

Nyquist Diagram

111
Q

Proponent of the Nyquist Diagram

A

Harry Nyquist

112
Q

For oscillation, the Nyquist Criterion is for ____ Feedback circuits, while the Barkhausen Criterion is for the ____ Feedback circuits

A

Nyquist Criterion is for Negative Feedback circuits

Barkhausen Criterion is for Positive Feedback circuits

113
Q

Nyquist Criterion for STABILITY in a Negative Feedback Circuit?

A

The Nyquist Curve (Derived from the diagram) must not enclose the (0, -1) coordinate point in the nyquist plot diagram

114
Q

What happens when a nyquist curve encoses (0, -1) in a nyquist diagram?

A

The Circuit will not Stabilize

115
Q

What does the (0, -1) point of a nyquist diagram represent?

A

It represents both the frequency and magnitude of β*Aol when the circuit introduces 180° Phase shift

116
Q

the mathematical restatement of Nyquist’s Criterion for STABILITY

A

abs ( β*Aol at 180° Phase shift ) ≤ 1

117
Q

The amount of dB between 0dB & the dB gain of the circuit operating at a frequency that procuces 180° Phase shift

A

Gain Margin

118
Q

What does the Gain Margin say about the situation of a Negative Feedback Circuit?

A

It dictates by how much we can increase the gain (dB) before the circuit becomes unstable

119
Q

The frequency of operation of a circuit that causes the output to have a 180° Phase shift

A

Phase Crossover Frequency

120
Q

The gain margin is (Positive/Negative) when the Negative feedback circuit is Stable(β*Aol < 1)

A

Positive

121
Q

It dictates by how much we can increase the phase lag before the circuit becomes unstable

A

Phase Margin

122
Q

Formula for Phase Margin

A

PM = 180° - (θ @ 0dB)

θ - phase shift at 0dB

123
Q

When a negative Feedback circuit is marginally stable, the circuit will _________

A

Oscillate

124
Q

An Operational Amplifier is a _____ Controlled _____ Source

A

Voltage Controlled Voltage Source

125
Q

The most common IC Op-Amp is ____

A

LM741C

126
Q

Zi of Ideal Op-Amp

A

Zi = ∞ ohms

127
Q

Zo of Ideal Op-Amp

A

Zo = 0 ohms

128
Q

Differential open-loop Gain (Ad) of Ideal Op-Amp

A

Ad = ∞

129
Q

CMRR of Ideal Op Amp

A

CMRR = ∞

130
Q

Common-mode open-loop Gain (Ac) of Ideal Op-Amp

A

Ac = 0 ohms

131
Q

The Op Amp Setup where one input terminal is grounded, and the other is applied with a signal

A

Single - Ended

132
Q

The Op Amp Setup where Both of input terminals are applied with a signal

A

Differental Op Amp

133
Q

Why is Common Mode Rejection needed?

A

Usually, noise is common to both input terminals, so to prevent the noise from being amplified as well, the common mode voltage must be rejected (Achieved by a low Common mode gain (Ac))

134
Q

Formula for Common mode Voltage(Vc)

A

Vc = (V₊ + V₋) / 2

V₊ - Voltage at non inverting input
V₋ - Voltage at inverting input
for noise, V₊ and V₋ is usually equal

135
Q

Formula for Common Mode Rejection Ratio (CMRR)

A 
CMRR = Ad / Ac
CMRR(db) = 20 log (Ad/Ac)
136
Q

With a practical Op amp, when the indended input signal is 0V, will the output be 0V?

A

No.

when Vd = 0:
Vo = Vc * Ac

Vc - Common voltage at the two inputs
Ac - Common-mode Gain

137
Q

Formula for Output Voltage of a Practical Op - Amp

A

Vo = VdAd + VcAc

Vc - Common voltage at the two inputs
Ac - Common-mode Gain
Vd - Differential Voltage at the two inputs
Ad - Differential Gain

138
Q

Formula for Differential Voltage at two inputs

A

Vd = V₊ - V₋

V₊ - Voltage at non inverting input
V₋ - Voltage at inverting input

139
Q

Zi of Practical Op-Amp

A

Zi = not infinity, but very high

140
Q

Zo of Practical Op-Amp

A

Zo = not zero, but very low

141
Q

CMRR of Practical Op Amp

A

CMRR = not infinity, but very high

142
Q

In an Ideal Op amp, do the input terminals require a minimum input current? if there is, what is it called?

A

No

143
Q

In an Parallel Op amp, do the input terminals require a minimum input current? if there is, what is it called?

A

Yes, the Current is called Input Bias Current

144
Q

Formula for Input Bias Current (minimum input current required to operate the Op Amp)

A

Input Bias Current = (Ib1 + Ib2) / 2

Ib1 and Ib2 - Base Currents inside an op amp

145
Q

Formula for Input Offset Current(Iio) (Absolute Difference of Base Currents)

A

Iio = abs(Ib1 - Ib2)

Ib1 and Ib2 - Base Currents inside an op amp

146
Q

The input offset current is a current that enters the ___________ resistor, producing an Offset voltage at the output

A

Feedback Resistor (Rf)

147
Q

Formula for output Offset Voltage (Voffset) due to Input offset Current

A

Voffset = Iio * Rf

Iio - input offset current
Rf - Feedback Resistor resistance

148
Q

If there is an error voltage Verror at the output of an op amp, ________ is the voltage input into the op amp that equivalently causes the output error voltage

A

Input Offset Voltage (Vin(offset))

149
Q

Formula for Input Offset Voltage(Vin(offset))

A

Vin(offset) = Verror / Ad

Verror - output error caused by an input offset voltage
Ad - differential voltage gain

150
Q

Formula for Maximum Peak to Peak Voltage (MPP)

A

Ideal:
MPP = Vcc₊ + Vee₋ = 2Vcc

Non-Ideal:
MPP = 2*(Vcc - 0.7)

151
Q

The Frequency/bandwidth of operation when the voltage gain of an op amp is setup to be 1 (0dB)

A

Unity Gain Frequency (fmax)

152
Q

Another term for Unity Gain Frequency

A

Gain Bandwidth Product or Unity Gain Bandwidth

153
Q

Formula for Unity Gain Frequency(fmax)

A

fmax (open loop)= Aol * fcutoff
fmax (closed loop)= Acl * fcutoff

Aol/Acl - open/closed loop gain
fcutoff - cutoff frequency

154
Q

The Unity Gain Frequency is Ideally __________

A

Infinity

155
Q

Formula for Effective Bandwidth

A

Effective BW = 0.35 / tr

tr - response time / rise time

156
Q

Formula for Power Supply Rejection Ratio

A

PSRR = (ΔInput Offset Voltage / ΔVsupply)

157
Q

Formula for % Gain Error

A

% Gain Error = Nominal Gain / G

¯_(ツ)_/¯

158
Q

The Slew Rate is ideally ________

A

Infinity

159
Q

The Slew Rate measures how ______

A

fast an Op-Amp can change Vo

160
Q

Formula for Slew Rate

A 
SR = ΔVo/Δt  
SR = (Acl * ΔVi) /Δt
SR = 2π * fmax * Vo

Acl - Closed loop voltage gain
fmax - unity gain frequency / gain bandwidth product

161
Q

The Default Value for Slew Rate of an Op Amp

A

0.5 V/μs

162
Q

Does the Gain Bandwidth Product/Unity gain frequency change when either input or output signal change?

A

NO

fmax is an inherent property of the Op Amp Setup

163
Q

For both Inverting or Non-Inverting Op Amp setup, Both Feedback Resistor and Series Resistor will ALWAYS BE connected at the ___________

A

Inverting Input Terminal

164
Q

Formula for Voltage Gain of an Inverting Op Amp

A

Acl = -Rf / Ra

Rf - Feedback Resistance
Ra - Series Resistance

165
Q

Formula for Voltage Gain of a Non-Inverting Op Amp

A

Acl = 1 + (Rf/Ra)

Rf - Feedback Resistance
Ra - Series Resistance

166
Q

Any resistors at the non-inverting op amp(as long as they do not feedback from the output) will (influence/not influence) the voltage gain of the circuit

A

not influence (always refer to resistors connected at the inverting op amp (Rf and Ra))

167
Q

In the event that there are resistors at the non-inverting op amp, what would they usually do to the input voltage at the non-inverting input?

A

They just serve as a voltage divider

168
Q

If all resistors in a subtracting amplifier were equal, what is the formula for the voltage output?

A

Vo = Vnoninverting - Vinverting

169
Q

If an Op Amp is to be set up as a Differentiator, What element serves as the feedback? what element serves as the series element?

A

Feedback: Resistor
Series: Capacitor

170
Q

If an Op Amp is to be set up as a Integrator, What element serves as the feedback? what element serves as the series element?

A

Feedback: Capacitor
Series: Resistor

171
Q

Formula for output voltage of a differentiator Op-Amp

A

Vo = -(dVi / dt)*RC

172
Q

Formula for output voltage of an Integrator Op-Amp

A

Vo = -(1 / RC) * ∫ Vi * dt

173
Q

With a buffer amplifier, a feedback wire connects the the output terminal and the __________ input terminal, while the other terminal serves as the input voltage

A

Inverting Input terminal

174
Q

Formula for Instrumentation Amplifier Voltage Output

A

Vo = (V2 - V1) * (1 + (2*R1 / Rgain)) *(R3 / R2)

175
Q

An Instrumentation Amplifier has ____ Op-Amps

A

Three

176
Q

Typical Open Loop Voltage Gain (Aol) of LM741C

A

Aol = 100,000

177
Q

Typical Unity Gain Frequency (fmax) of LM741C

A

fmax = 1 MHz

178
Q

Typical Input Impedance (Zin) of LM741C

A

Zin = 2 MΩ

179
Q

Typical Output Impedance (Zo) of LM741C

A

Zo = 75 Ω

180
Q

Typical Input Bias Current (Iib) of LM741C

A

Iib = 80 nA

181
Q

Typical Input Offset Current (Iio) of LM741C

A

Iio = 20 nA

182
Q

Typical Input Offset Voltage (Vin(offset)) of LM741C

A

Vin(offset) = 2 mV

183
Q

Typical CMRR of LM741C

A

CMRR = 90 dB

Bryx_Electronics (11 decks)

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