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
2
Q
Voltage Gain
A
Vout / Vin
in dB:
20 log (Vo/Vi)
3
Q
Power Gain
A
Po / Pi
in dB:
10 log (Po/Pi)
4
Q
Gain in Cascade
A
A1 x A2 x A3 . . .
in dB:
A1 + A2 + A3 . . .
5
Q
Device that amplifies input signal voltage
A
Voltage Amplifier
Duh!
6
Q
Device that amplifies input signal Power
A
Power Amplifier
What did you expect?
7
Q
Designed to amplify frequencies between 15 Hz to 20 kHz
A
Audio Amplifier
8
Q
Designed to amplify frequencies between 10 kHz to 100,000 MHz
A
Radio Frequency Amplifier (RF)
9
Q
Designed to amplify frequencies between 10 Hz to 6 MHz
A
Video Amplifier (also called Wide-band Amplifier)
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
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
12
Q
Amplifier where current in the output flows for 50% of the cycle (180 deg)
A
Class B Amplifier
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
14
Q
Device that generates AC from DC input
A
Oscillator
15
Q
LC Oscillator with Tapped Inductor
A
Hartley Oscillator
*H…Hinductor pwede din H for Henry. Your choice.
16
Q
LC Oscillator with Tapped Capacitor across an Inductor
A
Colpitts Oscillator
*C… opposite L pitts
17
Q
LC Oscillator with Tapped Capacitor across a Inductor-Capacitor series combination
A
Clapp Oscillator
*C…L…app
18
Q
Formula for Gain without Feedback (Aol) and Feedback Factor (β) for Hartley Oscillattor
A
Aol = Lo/Li β = Li/Lo
19
Q
Formula for Gain without Feedback (Aol) and Feedback Factor (β) for Colpitts Oscillators
A
Aol = Ci/Co β = Co/Ci
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)
21
Q
Crystal with greatest piezoelectric activity, the most unstable oscillator
A
Rochelle Salt
22
Q
Crystal with least piezoelectric activity, the toughest, and the most expensive, therefore the most stable oscillator,
A
Tourmaline
23
Q
Crystal material that have midway properties between Rochelle and Tourmaline, and is the cheapest among the three crystal materials
A
Quartz
24
Q
The Resonant Frequency of a piezoelectric crystal is __________ proportional to its thickness
A
Inversely proportional
25
Formula for The Open-loop Gain(Aol) and Feedback factor(β) of RC Phase-Shift Oscillator
```
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
26
Formula for The Open-loop Gain(Aol) and Feedback factor(β) of RC Wein bridge Oscillator
```
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
27
Types of Sampling in a Negative Feedback Amplifier Circuit
```
Voltage Sampling (Shunt)
Current Sampling (Series)
```
28
Types of Mixing in a Negative Feedback Amplifier Circuit input
```
Series Mixing (Voltage additive)
Shunt Mixing (Current series)
```
29
Formula for Voltage Gain with feedback (Af)
Af = A / (1 + BA)
30
Types of Feedback Connection
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
31
Gains and Feedback Factor in Voltage-Series Feedback Connection
Input and Output impedance
```
A = Vo / Vi
B = Vf / Vo
Af = Vo / Vs
```
Afv = A / (1 + BA)
```
Zin = Zi(1 + BA)
Zout = Zo / (1 + BA)
```
32
Gains and Feedback Factor in Current-Series Feedback Connection
Input and Output impedance
```
G = Io / Vi
B = Vf / Io
Af = Io / Vs
```
Afv = G / (1 + BG)
```
Zin = Zi(1 + BG)
Zout = Zo(1 + BG)
```
33
Gains and Feedback Factor in Voltage-Shunt Feedback Connection
Input and Output impedance
```
R = Vo / Ii
B = If / Vo
Af = Vo / Is
```
Afv = R / (1 + BR)
```
Zin = Zi / (1 + BR)
Zout = Zo / (1 + BR)
```
34
Gains and Feedback Factor in Current-Shunt Feedback Connection
Input and Output impedance
```
A = Io / Ii
B = If / Io
Af = Io / Is
```
Afv = A / (1 + BA)
```
Zin = Zi / (1 + BA)
Zout = Zo(1 + BA)
```
35
Gain Margin (Formula)
GM = 1 / β*Aol
in dB:
GM = - 20log(β*Aol)
36
An OSCILLATOR employs _______ Feedback
pOSItive Feedback
"pOSItive, OSCIllator"
37
Formula for Feedback Gain(Af) of a Positive Feedback Oscillator
Af = A / ( 1 - βA)
A - Open Loop Gain / Gain Without Feedback
β - Feedback Element Gain (Less than or equal to 1)
38
What βA is required in a Positive Feedback Oscillator so that the Oscillator self-oscillates
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)
39
Barkhausen Criterion
| there are 2
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)
40
A Positive Feedback Oscillator usually has a circuit called a _________
Tank Circuit
41
The principle of oscillation the tank circuit employs
Flywheel Effect
42
The reason why the Flywheel effect dampens is due to the ________
Resistance in the coil of the inductor
43
To decrease the Damping effect of the coil resistance in the inductor, the __________ must be increased
Quality factor
| Q = XL / Rcoil
44
The output of a Harmonic Oscillator is _____
Sinusoidal
45
The output of a Relaxation Oscillator is _____
Digital
46
In Positive Feedback, the Feedback Signal must be ______ with the incoming input signal
In Phase
47
Another term for ' Q '
Figure of Merit
48
Two types of RC Positive Feedback Oscillators
- Phase Shift Oscillators
| - Wein Bridge Oscillators
49
A Phase Shift Oscillator's passive network consists of ____ Lead (and/or) ____ Lag Circuits
3 Lead Circuits
OR
3 Lag Circuits
50
The Passive network of a Phase Shift Oscillator must provide a total of ______° Phase Shift (____° for each lead/lag circuit used)
180° Phase Shift (60° Phase shift per lead/lag circuit)
51
A Phase Shift Oscillator's OP-Amp configuration is in a/an ____________
Inverting Amplifier
| Aol = -Rf / Rs
52
Formua for The Resonant Frequency(fr) of a Phase Shift Oscillator
fr = 1 / ( 2πRC*√6 )
R - resistor used in the passive Lead/Lag Network
C - capacitor used in the passive Lead/Lag Network
53
A Wein Bridge Oscillator's passive network consists of ____ Lead (and/or) ____ Lag Circuits
1 Lead Circuit AND 1 Lag Circuit
54
A Wein Bridge Oscillator's OP-Amp configuration is in a/an ____________
Non - Inverting Amplifier
| Aol = 1 + (Rf / Rs)
55
Formua for The Resonant Frequency(fr) of a Wein Bridge Oscillator
fr = 1 / ( 2π*√[Rlead*Clead*Rlag*Clag] )
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] )
56
Four common LC Positive Feedback Oscillators
- Hartley Oscillator
- Colpitts Oscillator
- Clapp Oscillator
- Armstrong Oscillator
57
A Hartley Oscillator's feedback circuit consists of: _____
(Capacitor) in parallel to (two inductors(Li, Lo), with ground tapped between them)
58
A Colpitts Oscillator's feedback circuit consists of: ______
(Inductor) in parallel to (two Capacitors(Ci, Co), with ground tapped between them)
59
A Clapp Oscillator's feedback circuit consists of: ______
(A capacitor in series to an inductor{CLapp}) in parallel to (two Capacitors(Ci, Co), with ground tapped between them)
60
An Armstrong Oscillator uses a __________, a component not present in the other three LC Oscillators
Transformer
61
Formula for Resonant Frequency of a Hartley Oscillator
fr = 1 / { 2π*√(Leq*C) }
Leq = Li +Lo +2M
M = k*√(Li*Lo)
k - coupling factor (1 by default/not specified)
62
Formula for Resonant Frequency of a Colpitts Oscillator
fr = 1 / { 2π*√(L*Ceq) }
Ceq = (Ci*Co / (Ci + Co))
63
Formula for Resonant Frequency of a Clapp Oscillator
fr = 1 / { 2π*√(L*Ceq) }
Ceq = 1 / { (1/Ci) + (1/Co) + (1/C) }
64
Formula for Resonant Frequency of an Armstrong Oscillator
fr = 1 / 2π*√(Lpri*C)
Lpri - Inductance of the primary coil of the transformer
65
Effective Crystal lumped sum circuit
```
1st Branch: L (series) Cs (series) R
2nd Branch(parallel to 1st branch): Miller Capacitance (Cm)
```
66
Formula for Crystal oscillator series resonant frequency
frs = 1 / 2π*√(L*Cs)
Cs - Capacitance in series with the stray conductance in a crystal oscillator
67
When a Crystal Oscillator is operating at the Series Resonant Frequency, its impedance is __________
Z = 0 Ω
68
The Series Resonant Frequency is (> , < , = ) the Parallel Resonant Frequency of the Crystal Oscillator
Less than
69
Formula for Crystal oscillator series resonant frequency
frs = 1 / 2π*√(L * [Cs*Cm / (Cs + Cm)] )
Cs - Capacitance in series with the stray conductance in a crystal oscillator
Cm - Miller Capacitance in parallel to the Crystal Oscillator
70
When a Crystal Oscillator is operating at the Parallel Resonant Frequency, its impedance is __________
Z = ∞ Ω
71
The most stable Positive Feedback Oscillator
Pierce Crystal Oscillator
| AKA Crystal Controlled Oscillator
72
With a Pierce Crystal Oscillator, a Crystal replaces the ______ in a Colpitts Oscillator
Inductor
73
Due to the Lumped Circuit of the Crystal, the whole oscillator setup will look like a ______ Oscillator
Clapp:
| (Lcrystal in series with Ccrystal) || (Two capacitors)
74
Another Term for Relaxation Oscillator
Multivibrator ( ͡° ͜ʖ ͡°)
75
A Multivibrator ( ͡° ͜ʖ ͡°) uses ___ Amplifiers and ____ Passive Networks
Two Amplifiers (only one is "turned on"( ͡° ͜ʖ ͡°) at any given time) and two Passive Networks
76
A Multivibrator ( ͡° ͜ʖ ͡°) employs ______ Feedback
positive
77
When the two passive networks of a multivibrator ( ͡° ͜ʖ ͡°) are both Resistors, the Multivibrator ( ͡° ͜ʖ ͡°) is considered as operating in ________ mode
Bistable
78
When the two passive networks of a multivibrator ( ͡° ͜ʖ ͡°) are both Capacitors, the Multivibrator ( ͡° ͜ʖ ͡°) is considered as operating in ________ mode
Astable
79
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
Monostable
80
Multivibrators ( ͡° ͜ʖ ͡°) are either _______ or _______ when it comes to triggering
Self-Excited or Driven
81
The State of the Multivibrator ( ͡° ͜ʖ ͡°) that does not change unless circuit is disturbed
Stable
82
The State of the Multivibrator ( ͡° ͜ʖ ͡°) That remains unchanged, only for a certain amount of time
Quasi-Stable
83
A Bistable Multivibrator ( ͡° ͜ʖ ͡°) is also known as a _________, and has _____ Stable states and ______ Quasi-Stable States
- Flip-Flop, Binary, or Eccless-Jordan Multivibrator ( ͡° ͜ʖ ͡°)
- 2 Stable States, 0 Quasi-Stable States
84
A Monostable Multivibrator ( ͡° ͜ʖ ͡°) is also known as a _________, and has _____ Stable states and ______ Quasi-Stable States
- One-Shot or Single-shot
| - 1 Stable States, 1 Quasi-Stable States
85
An Astable Multivibrator ( ͡° ͜ʖ ͡°) is also known as a _________, and has _____ Stable states and ______ Quasi-Stable States
- Free-Running
| - 0 Stable States, 2 Quasi-Stable States
86
Negative Feedback Amplifiers are proposed by ________
Harold Black (1937)
87
Another term for negative feedback
degenerative feedback
88
Negative feedback setup are used for _________
Purely resistive amplifier networks
89
Advantages of Negative Feedback over Positive Feedback
- More Stable Voltage Gain
- Wider BW
- Lower Noise
- More Linear Operation
90
For a Negative Feedback, the feedback signal is _______ with respect to the incoming input signal
Out of Phase
91
Formula for Feedback Gain(Af) of a Negative Feedback Oscillator
Af = A / ( 1 + βA)
A - Open Loop Gain / Gain Without Feedback
β - Feedback Element Gain (Less than or equal to 1)
92
For the Negative Feedback Gain Formula ( Af = A / ( 1 + βA) ), The factor (1 + βA) is called the _______
Sacrifice Factor/Desensitivity Factor
93
A [Voltage - {either series or shunt}] Feedback circuit has 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
A [Current - {either series or shunt}] Feedback circuit has 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
A [{either Voltage or Current} - Series] Feedback circuit has 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
A [{either Voltage or Current} - Shunt] Feedback circuit has 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
For Negative Feedback setup, Mixing occurs at the (input/output)
Input
98
For Negative Feedback setup, Sampling occurs at the (input/output)
Output
99
General Zi or Zo (Zio) formula of a Negative Feedback Amplifier (My own version)
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
For Voltage-Series Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)
Input: Voltage
Output: Voltage
101
For Voltage-Shunt Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)
Input: Current
Output: Voltage
102
For Current-Series Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)
Input: Voltage
Output: Current
103
For Current-Shunt Setup, the Input signal is a (Voltage/Current) and the output signal is a (Voltage/Current)
Input: Current
Output: Current
104
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):
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
The Betas (β) of the four Negative Feedback Amplifiers
Voltage - Series: β = Vfeed / Vo
Voltage - Shunt: β = Ifeed / Vo
Current - Series: β = Vfeed / Io
Current - Shunt: β = Ifeed / Io
106
The Closed loop gain (total gain w/ feedback (Af)) of the four negative feedback amplifiers
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
If β*Aol is muchmuch greater than 1, the estimate formula for the total gain w/ feedback(Af) is equal to:
Af = 1 / β
108
The total gain w/ feedback(Af) is uninfluenced by the parameters of the __________
Amplifiers (Parameters like β, α, and γ for transistors)
109
The best amplifier to be used among the four Negative Feedback Amplifiers is the _________
Voltage Series Amplifier
| High Zi, Low Zo are the properties of an ideal OP amp
110
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
Nyquist Diagram
111
Proponent of the Nyquist Diagram
Harry Nyquist
112
For oscillation, the Nyquist Criterion is for ____ Feedback circuits, while the Barkhausen Criterion is for the ____ Feedback circuits
Nyquist Criterion is for Negative Feedback circuits
| Barkhausen Criterion is for Positive Feedback circuits
113
Nyquist Criterion for STABILITY in a Negative Feedback Circuit?
The Nyquist Curve (Derived from the diagram) must not enclose the (0, -1) coordinate point in the nyquist plot diagram
114
What happens when a nyquist curve encoses (0, -1) in a nyquist diagram?
The Circuit will not Stabilize
115
What does the (0, -1) point of a nyquist diagram represent?
It represents both the frequency and magnitude of β*Aol when the circuit introduces 180° Phase shift
116
the mathematical restatement of Nyquist's Criterion for STABILITY
abs ( β*Aol at 180° Phase shift ) ≤ 1
117
The amount of dB between 0dB & the dB gain of the circuit operating at a frequency that procuces 180° Phase shift
Gain Margin
118
What does the Gain Margin say about the situation of a Negative Feedback Circuit?
It dictates by how much we can increase the gain (dB) before the circuit becomes unstable
119
The frequency of operation of a circuit that causes the output to have a 180° Phase shift
Phase Crossover Frequency
120
The gain margin is (Positive/Negative) when the Negative feedback circuit is Stable(β*Aol < 1)
Positive
121
It dictates by how much we can increase the phase lag before the circuit becomes unstable
Phase Margin
122
Formula for Phase Margin
PM = 180° - (θ @ 0dB)
θ - phase shift at 0dB
123
When a negative Feedback circuit is marginally stable, the circuit will _________
Oscillate
124
An Operational Amplifier is a _____ Controlled _____ Source
Voltage Controlled Voltage Source
125
The most common IC Op-Amp is ____
LM741C
126
Zi of Ideal Op-Amp
Zi = ∞ ohms
127
Zo of Ideal Op-Amp
Zo = 0 ohms
128
Differential open-loop Gain (Ad) of Ideal Op-Amp
Ad = ∞
129
CMRR of Ideal Op Amp
CMRR = ∞
130
Common-mode open-loop Gain (Ac) of Ideal Op-Amp
Ac = 0 ohms
131
The Op Amp Setup where one input terminal is grounded, and the other is applied with a signal
Single - Ended
132
The Op Amp Setup where Both of input terminals are applied with a signal
Differental Op Amp
133
Why is Common Mode Rejection needed?
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
Formula for Common mode Voltage(Vc)
Vc = (V₊ + V₋) / 2
V₊ - Voltage at non inverting input
V₋ - Voltage at inverting input
for noise, V₊ and V₋ is usually equal
135
Formula for Common Mode Rejection Ratio (CMRR)
```
CMRR = Ad / Ac
CMRR(db) = 20 log (Ad/Ac)
```
136
With a practical Op amp, when the indended input signal is 0V, will the output be 0V?
No.
when Vd = 0:
Vo = Vc * Ac
Vc - Common voltage at the two inputs
Ac - Common-mode Gain
137
Formula for Output Voltage of a Practical Op - Amp
Vo = Vd*Ad + Vc*Ac
Vc - Common voltage at the two inputs
Ac - Common-mode Gain
Vd - Differential Voltage at the two inputs
Ad - Differential Gain
138
Formula for Differential Voltage at two inputs
Vd = V₊ - V₋
V₊ - Voltage at non inverting input
V₋ - Voltage at inverting input
139
Zi of Practical Op-Amp
Zi = not infinity, but very high
140
Zo of Practical Op-Amp
Zo = not zero, but very low
141
CMRR of Practical Op Amp
CMRR = not infinity, but very high
142
In an Ideal Op amp, do the input terminals require a minimum input current? if there is, what is it called?
No
143
In an Parallel Op amp, do the input terminals require a minimum input current? if there is, what is it called?
Yes, the Current is called Input Bias Current
144
Formula for Input Bias Current (minimum input current required to operate the Op Amp)
Input Bias Current = (Ib1 + Ib2) / 2
Ib1 and Ib2 - Base Currents inside an op amp
145
Formula for Input Offset Current(Iio) (Absolute Difference of Base Currents)
Iio = abs(Ib1 - Ib2)
Ib1 and Ib2 - Base Currents inside an op amp
146
The input offset current is a current that enters the ___________ resistor, producing an Offset voltage at the output
Feedback Resistor (Rf)
147
Formula for output Offset Voltage (Voffset) due to Input offset Current
Voffset = Iio * Rf
Iio - input offset current
Rf - Feedback Resistor resistance
148
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
Input Offset Voltage (Vin(offset))
149
Formula for Input Offset Voltage(Vin(offset))
Vin(offset) = Verror / Ad
Verror - output error caused by an input offset voltage
Ad - differential voltage gain
150
Formula for Maximum Peak to Peak Voltage (MPP)
Ideal:
MPP = Vcc₊ + Vee₋ = 2Vcc
Non-Ideal:
MPP = 2*(Vcc - 0.7)
151
The Frequency/bandwidth of operation when the voltage gain of an op amp is setup to be 1 (0dB)
Unity Gain Frequency (fmax)
152
Another term for Unity Gain Frequency
Gain Bandwidth Product or Unity Gain Bandwidth
153
Formula for Unity Gain Frequency(fmax)
fmax (open loop)= Aol * fcutoff
fmax (closed loop)= Acl * fcutoff
Aol/Acl - open/closed loop gain
fcutoff - cutoff frequency
154
The Unity Gain Frequency is Ideally __________
Infinity
155
Formula for Effective Bandwidth
Effective BW = 0.35 / tr
tr - response time / rise time
156
Formula for Power Supply Rejection Ratio
PSRR = (ΔInput Offset Voltage / ΔVsupply)
157
Formula for % Gain Error
% Gain Error = Nominal Gain / G
¯\_(ツ)_/¯
158
The Slew Rate is ideally ________
Infinity
159
The Slew Rate measures how ______
fast an Op-Amp can change Vo
160
Formula for Slew Rate
```
SR = ΔVo/Δt
SR = (Acl * ΔVi) /Δt
SR = 2π * fmax * Vo
```
Acl - Closed loop voltage gain
fmax - unity gain frequency / gain bandwidth product
161
The Default Value for Slew Rate of an Op Amp
0.5 V/μs
162
Does the Gain Bandwidth Product/Unity gain frequency change when either input or output signal change?
NO
| fmax is an inherent property of the Op Amp Setup
163
For both Inverting or Non-Inverting Op Amp setup, Both Feedback Resistor and Series Resistor will ALWAYS BE connected at the ___________
Inverting Input Terminal
164
Formula for Voltage Gain of an Inverting Op Amp
Acl = -Rf / Ra
Rf - Feedback Resistance
Ra - Series Resistance
165
Formula for Voltage Gain of a Non-Inverting Op Amp
Acl = 1 + (Rf/Ra)
Rf - Feedback Resistance
Ra - Series Resistance
166
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
not influence (always refer to resistors connected at the inverting op amp (Rf and Ra))
167
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?
They just serve as a voltage divider
168
If all resistors in a subtracting amplifier were equal, what is the formula for the voltage output?
Vo = Vnoninverting - Vinverting
169
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?
Feedback: Resistor
Series: Capacitor
170
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?
Feedback: Capacitor
Series: Resistor
171
Formula for output voltage of a differentiator Op-Amp
Vo = -(dVi / dt)*RC
172
Formula for output voltage of an Integrator Op-Amp
Vo = -(1 / RC) * ∫ Vi * dt
173
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
Inverting Input terminal
174
Formula for Instrumentation Amplifier Voltage Output
Vo = (V2 - V1) * (1 + (2*R1 / Rgain)) *(R3 / R2)
175
An Instrumentation Amplifier has ____ Op-Amps
Three
176
Typical Open Loop Voltage Gain (Aol) of LM741C
Aol = 100,000
177
Typical Unity Gain Frequency (fmax) of LM741C
fmax = 1 MHz
178
Typical Input Impedance (Zin) of LM741C
Zin = 2 MΩ
179
Typical Output Impedance (Zo) of LM741C
Zo = 75 Ω
180
Typical Input Bias Current (Iib) of LM741C
Iib = 80 nA
181
Typical Input Offset Current (Iio) of LM741C
Iio = 20 nA
182
Typical Input Offset Voltage (Vin(offset)) of LM741C
Vin(offset) = 2 mV
183
Typical CMRR of LM741C
CMRR = 90 dB
