Questions tagged [gain]
Simply the ratio of output signal to input signal, this dimensionless quantity is a measure of the amplification of a signal which may be represented by voltage, current of may even have a digital representation. A very general concept sometimes used to describe attenuation (when gain < 1)
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Input and Output impedances of Current and Voltage Amplifiers
I read that Voltage Amplifier have high input impedance and low output impedance, and Current Amplifier have low input impedance and high output impedance. If this is true what is reason for this as I ...
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2answers
85 views
How to design voltage gain circuit?
I need to build a circuit with a DC gain of 2 for a 0-5V input, 0-10 V ouput (input will be adjustable). Current can be low since it doesn't really matter (this will be purely as a control signal). ...
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2answers
52 views
Bode diagram calculating for random frequency
The max Gain of an opamp is 100dB (=100000). I have a cutting frequency at 10 Hz and then the slope of my bode diagram decrease by -20dB/dec . I have unity gain at 1MHz.
For 100 Hz its increasing by ...
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1answer
39 views
Is this way of plotting AC current gain in LTspice correct?
I want to plot the AC current gain versus the collector current in common base configuration. Ac current gain "alpha ac" for CB configuration is defined as the change occurring in collector current IC ...
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1answer
34 views
Finding out antenna gain in 3-D space (azimuth and elevation)
I found a cross-sectional view of a patch antenna's gain below. I would like to know how can I determine the antenna's gain for every azimuth and elevation angle in 3-D space?
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2answers
156 views
Gain of Non-Inverting Amplifier Does Not vary with Resistor Values
I am trying to build a non-inverting amplifier using a LM7171 op amp, and I am implementing it with potentiometers as Rf and R2 so that I can smoothly control the gain of the amplifier (and easily ...
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2answers
1k views
Single supply non-inverting amplifier using op amp
I'm working on building a distortion guitar effect pedal for an analog electronics class I'm taking. I am struggling with building an amplifying circuit using an op amp (we just began learning about ...
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2answers
151 views
What's the largest practical stable gain possible?
I have a feedback application to set the voltage of a node in which there is considerable loss in the loop. Simulations tell me that a differential voltage gain of 10000, 80dB (roughly about what you ...
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38 views
Calculating the gain of a transistor in VGA
This paper is from IEEE:
The gain of the first VGA is expressed as \$ A_1 = \frac{gm_1 R_1}{1+gm_1 R_2+\frac{R_2}{ro_1}} \$
However, I thought that since the (DC) current source at the source of ...
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32 views
Gain and output impedance in a differential amplifier
When looking at a differential amplifier:
Why does gain increase when the output impedance is increased?
For example, replacing a differential amplifier biased with resistors for an active load (...
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1answer
56 views
What's the actual difference between voltage gain, current gain and power gain?
Why do we intend to obtain different gains at different places?
In an emitter follower for example,
There's no voltage gain, but there's current gain and therefore it has power gain. Okay, how's ...
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3answers
309 views
Opamp stability given in not inverting configuration
If a datasheet (like AD828) says that an opamp is stable at Gain >2 (or reccomends to work with G>2, hence it is clearly not unity gain stable), what can we deduct about its stability in the inverting ...
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1answer
78 views
Calculating gains for Op-amps with real AC voltages
I'm a uni student trying to figure out how to calculate gains of op-amps with recorded real AC voltage inputs and outputs. We are expected to somehow know this for some post-lab work without being ...
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0answers
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Rise in Loop Gain (Part 2?)
All,
I am going through an older textbook and am looking at some examples regarding stability. I can successfully model the circuit in the book and get the same results as the author. In this case ...
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1answer
84 views
BJT differential amplifier: What causes common mode voltage gain?
In any normal op amp, if it was ideal it would have a gain such that the output voltage would be
However in reality this is not the case as there is a common mode voltage gain and hence in reality ...
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25 views
Shunt Shunt Feedback SImulations
I am trying to simulate the solution to an old text book example on a simple Shunt-Shunt feedback amplifier.
simulate this circuit – Schematic created using CircuitLab
The book only shows BF = ...
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1answer
19 views
Conversion Gain Definition for DSB-SC Upconversion
If I multiply a baseband signal \$A cos(C\omega t)\$ and a carrier signal \$B cos(D\omega t)\$, the result is \$\frac{AB}{2} [cos(C-D)\omega t+cos(C+D)\omega t]\$, which is a double sideband, ...
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1answer
31 views
Is it possible to change gain on Adafruit PN532
Is it possible to change the gain on an Adafruit PN532 board?
I need to LIMIT the range in order for it to NOT interfere with another PN532 installed close by.
The board is to be used with an ...
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1answer
57 views
Whats the gain of this op amp?
what i did here is take current over the 4.7 kilo ohm and since there are no other voltage input other than the one then shouldn't the Vout be 0.2127 volts? thats not possible for a non-inverting ...
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1answer
54 views
Tail resistor in differential gain
Why doesn't the tail resistor feature in the denominator for differential gain (whereas it does for common mode gain) in the differential amplifier below? (Fig 5N.28 from Learning the Art of ...
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2answers
133 views
Fitting of continuous transfer function
I measure a network's transfer function using a network analyzer and therefore have a set of complex data points, representing the network's gain and phase. I wish to fit a continuous, rational ...
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2answers
61 views
Output of AC op amp circuit has unknown superimposed signal on top of expected output signal
I am trying to find the voltage gain of a certain ideal op amp circuit with a sinusoidal input. However, when I simulate the circuit, the output shown seems to be my calculated output but with a ...
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1answer
62 views
Large dynamic range current sense 1uA - 100mA
I am looking at large dynamic circuits and came across an interesting project by ETH Zurich called the rocket logger - https://rocketlogger.ethz.ch/
I am a little confused by their current sensing ...
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1answer
91 views
Op Amp output's noise changes when the gain changes
I use Arduino DUE to generate a 100 Hz pulse.
I wanted to remove the DC value so I added a high pass filter and this is connected to the Op Amp(ADA4000-1)'s input. A RIGOL's DP832 power supply is ...
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2answers
63 views
How to calculate Op Amp's gain using Arduino's ADC
Hi, I'm feeding a 500 Hz PWM signal to the Op Amp's V_IN using Arduino DUE.
The Op Amp, which is ADA4000-2 from Analog device, is connected to +12V, -12V using an external power supply.
The power ...
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3answers
57 views
zero AC gain of CMOS inverter
Why is the following AC analysis of CMOS inverter resulted in zero AC gain (vout/vin) ?
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0answers
30 views
Gain bandwidth product of amplifier in a DC scenario
I think I have a simple (but still to me confusing) question regarding the gain bandwidth product (GBP) of an instrumentation amplifier: Datasheet (AD8237)
I have sensors that change their output ...
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0answers
75 views
How does this circuit with inverters work?
What this does this circuit do? I suspect it is an amplifier, but don't know how it amplifies.
For example Inv 5 and Inv 6 are connected in parallel with reverse sides but there is a wire between ...
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2answers
83 views
High voltage gain block
Schematic 1 shows a discrete operational amplifier which is used as a gain block to make up to 450V out of 12V. Q3 and Q4 are used to generate a current which is used by the current mirror. This is ...
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1answer
45 views
DC Gain too low at higher voltages
I am having an issue with DC gain for a non-inverting op amp circuit. All I am trying to do is double the voltage from two DAC outputs (DAC range is 0 to 5V and I want it to be ~0V to 10V). The DAC ...
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2answers
61 views
Why Im getting shifted phase in the output voltage?
Why im getting shifted phase in the output voltage in this differential amplifier?
and how can I eliminate this shifted phase?
Second question is, I need to make a gain of 50 in the amplifier below, ...
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0answers
29 views
Measure the 'gain' of this circuit
I made this schematic using Ni multisim and I got asked to find the ‘gain of this circuit using a 1v p-p 1kHz sine signal’ and I was unsure about this because I’m not sure if it means voltage gain or ...
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3answers
76 views
perceived loudness of noise vs. sine wave
I am trying to understand what gains I need to use each for a white noise generator and a pink noise generator for a human ear to perceive the loudness to be the same as it is for a 440 Hz sine wave ...
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0answers
34 views
What is the Correct method to find the poles and zeros expressions?
What is the Correct method to find the poles and zeros expressions ?
This is a replica circuit method used to calculate loop gain, please only consider the above part.
I used pspice to find the bode ...
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2answers
96 views
Controlling an output based on level of AC signal
This is my first post on this StackExchange after years of lurking, so please be gentle!
I would like to be able to enable an output (for example an LED) based upon an AC voltage from a split-core ...
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2answers
272 views
How to achieve variable gain using a micro-controller [closed]
I have a sine signal Vsignal below which is AC coupled and will be buffered by an LT1490 to the line input of a MOSFET power amplifier.
I'm able to control the frequency of the Vsignal through ...
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1answer
99 views
How can I build BJT amplifier with Vin and Vout requirements (peak to peak values)
I have been working on a project but I'm not sure if I'm complying with the requirements that I was given.
Design a BJT amplifier such that VIN=0.1 V and VOUT=5 V (peak to peak values). ...
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2answers
60 views
Is it better to control an amplitude of audio signal or gain?
I'm creating simple headphones amplifier with an opamp (basic non-inverting config with RC high-pass on NI) and I wonder, what's better - to control an amplitude of input signal, or a gain of an opamp?...
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1answer
66 views
Effect of changing current sense resistor value in amplifier circuit
I am trying to implement a current output amplifier circuit shown below. Current is measured across sense resistor Rs to adjust input voltage Vin.
Gain: G = -Iout/Vin = R2/(Gain-of-IA1*R1*RS)
The ...
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0answers
45 views
Choosing gain to get desired system response
I have to choose a gain so the step response fits a couple of criterias. The criterias are:
Maximum overshoot 20%
Settling time between 0.8s and 1.3s
Rise time between 0.8s and 1.1s
At first I tried ...
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5answers
660 views
Using an opamp with fractionnal gain with supply less than input signal
Let's say we have an AC signal that can swing from -15v to +15v max peak to peak. If I use an opamp with the power rails to -5v and +5v, can I get a non clipped output signal if I use a gain of 0.333? ...
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3answers
530 views
LM324 instrumentation amplifier gain and offset problem
I want to translate a Pt100 RTD to a 0-10V range, to be read by a PLC.
I designed a circuit (instrumentation amplifier) using the LM324 op-amp. It is powered using a single 12V supply.The resistor ...
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1answer
45 views
Receiver Antenna Gain
How is gain defined for a receiver antenna?
If we look at a radiating antenna, there is a Pin, and the gain in a particular direction would be the radiation intensity Ur, divided by the radiation ...
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0answers
68 views
Convention of closed loop gain in op-amp for inverting configuration
I tried to analyze real op-amp equations, in inverting and non-inverting configurations.
I found a reference question here in which they were calculating exactly what I wanted to do: calculating the ...
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1answer
72 views
MP111 Op-Amp: Non-linear gain at low input voltages?
I'm currently using the MP111 hybrid op-amp set up as a voltage controlled current source with a gain of 1. But what I'm finding is that at low input voltages the gain is much higher than it should ...
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0answers
179 views
yagi antenna gain formula
is there any specific formula to calculate yagi-uda antenna Gain? i know that The Gain of Yagi Antenna depends on length of antenna array and do not depend on number of directors used in the design , ...
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2answers
184 views
How to design a circuit starting from a block diagram?
I am struggling with the following self-study problem, taken from The Analysis and Design of Linear Circuits (8th edition).
There are two things that shock me from this problem.
We need to get a ...
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1answer
75 views
Vpp of oscillation of LCR circuit
Edited:
I'm having a trouble to estimate Vpp of a RCL oscillation circuit. I found a peak to peak inductor voltage (Vpp_L) varies with the different combination of LC, which makes sense because the ...
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1answer
39 views
How to calculated weighted gain of antenna?
I have this test specification for testing antennas and it defines weighted gain as follows:
The weighted gain is calculated from the transfer function (S21) using only the gain values within the ...
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0answers
58 views
Maximum mid-band gain of s.s. model MOSFET amplifier?
Schematics
I need to find the maximum possible gain for this NMOS cascode circuit.
Here is the s.s. model:
Work
I used nodal-matrix analysis (basis is KCL) to find the gain (\$A_v\$):
$$
\...
