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

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2
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1answer
81 views

Mic preamp, fixing noise and gain issues

I'm trying to fix a preamp (made by a colleague) that's noisy and somehow not amplifying enough. I should say right away that this project is pushing the edge of my electronics knowledge so I have a ...
0
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0answers
81 views

Current Series Feedback Calculation Puzzle

I'm following a text on negative feedback amplifier analysis and the author describes the following example of a current (sampling) series (mixing) feedback circuit; the humble CE amplifier: ...
2
votes
1answer
97 views

Why Bandwidth Affects Response Speed

This is a follow-up question to (this question). Here is the amplifier section in question: In the answer, the author (@Brian Onn) gives the following explanation: "Slow vs. fast is not about ...
3
votes
1answer
87 views

Gain tuning issues of op-amp

I am currently building a simple gain stage with an op-amp (MAX414CPD+-ND) following this circuit diagram simulate this circuit – Schematic created using CircuitLab By adjusting the 10K ...
1
vote
1answer
46 views

Forced beta too small

Let's take an example in which the recommended beta for a transistor's(NPN) saturation is 10.If you use a forced beta smaller than 10,will the transistor still be saturated succesfully?Can hFE be ...
0
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0answers
33 views

Ziegler Nichols PI Tuning : Integral gain too high

I am tuning my PI controller in MATLAB using Ziegler Nichols method in which my plant is the car Engine and I have to stabilize the engine speed to lets say 900 when throttle is not pressed. In order ...
0
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2answers
54 views

How is the solution for \$\alpha\$ and \$\beta\$ current gain of a BJT derived?

I'm just an enthusiast, and not too good at maths; I'm exploring constant current source circuits, in doing so I came across two equations for BJT current gain: Could someone help me understand how ...
0
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1answer
75 views

A confusion on the current gain of an NPN transistor

In above screenshot V2 is increasing ramp voltage from 0 to 12V, which accordingly increases Ib. Transistor is an NPN type. Ic(q1) is the collector current. Vce = V1 is a constant 1V. So it means ...
-3
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2answers
80 views

No plot for DC current gain in datasheet

Here is the data-sheet: https://www.fairchildsemi.com/datasheets/2N/2N4401.pdf I want to use a 2N4401 NPN transistor in active region for amplification, and I want to know its beta(DC current gain) ...
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0answers
134 views

Did I mess up my lab experiment ? (active low pass filter)

This is the table of the readings and I have worked out the gain which is $$\frac{Vout}{Vin}$$ and I got all 5 at the beginning ... but I also remember that the values of the resistors in the feedback ...
3
votes
1answer
80 views

Wien bridge sinusoidal oscillator

simulate this circuit – Schematic created using CircuitLab I would check that in the Wien bridge sinusoidal oscillator the gain A_V=1+(R5+R4)/R3) is actually A_V=3 as the Barkhausen ...
0
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2answers
48 views

finding the gain of a two stage voltage amplifier

i currently do not know how to approach this question, in terms of simplifying the circuit and which formulas to use in order to find the gain
3
votes
2answers
48 views

average of dBs or dB of average?

In several papers, books etc. I have encountered to expression of "average gain of the path is ... dB", now I wonder this is the average of dBs or dB of averages? The sources have not mentioned ...
1
vote
1answer
62 views

unfamiliar gain equation of differential amplifier

I am examining op amps and I found this pdf very helpful: http://www.aicdesign.org/SCNOTES/2010notes/Lect2UP230_(100327).pdf In this tutorial, the op amp circuit topology is given as this: and ...
0
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0answers
41 views

midband gain calculation of feedback amp

I cannot wrap my head around this. how did they calculate the gain of Q1? can anyone explain the big picture? the math is already shown but I cannot see the breakdown of it. rpi1=2.3K and rpi2=1.23k ...
0
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1answer
44 views

Finding the voltage gain at low frequencies

can anyone explain how the second expression for the gain is obtained? they multiplied or divided the first equation and came up with second one.
0
votes
2answers
86 views

designing a variable gain amplifier

I want to build a variable gain amplifier. My first thought was to build two feedback resistors and switch one or the other off with a MOSFET. However, the MOSFETs have shunt diodes which are going ...
0
votes
2answers
56 views

What is the relation between the gain and range of a data-acquisition amplifier?

A data-acquisition amplifier has different ranges. The board amplifiers a voltage sample and ADC converts it to a digital code. There is probably a reference voltage inside the board so it compares ...
4
votes
1answer
248 views

Why Increasing Collector Voltage Reduces Collector-base Capacitance

I'm looking at some transistor radio circuits and the book I'm following makes the following statement with regard to AC gain: "By raising the DC voltage at the collector, the internal collector-base ...
1
vote
1answer
76 views

CE Amplifier voltage gain is not as calculated

Am trying to learn from what i read by simulating a common-emitter-amplifier using 2N3055A that has Bdc(DC Current Gain) of 20 - 70. I fallowed the steps below but the Voltage gain is not even close ...
1
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3answers
77 views

RF FETs - how exactly are they different from regular FETs?

I've browsed through DigiKey and there are these RF FETs. Are they for final stage amplification? Say you have an opamp that doesn't go for the final desired voltage, so one uses these FETs as Common ...
1
vote
3answers
84 views

Gain equation of cascode common emitter amplifier with an LC tank

I'm trying to find the gain equation of the circuit presented below. I know that for a cascode common emitter amplifier without resistor RE and with a current source instead of the LC tank, the ...
1
vote
0answers
114 views

Designing a Multistage Amplifier

I have to design a BJT multistage amplifier to meet a specification provided by my professor. The first stage is to be a differential amplifier, and the second stage is to be a common collector ...
0
votes
0answers
37 views

Resistively loaded common source amplifier design

I have to design a resistively loaded common source amplifier with an NMOS and the specs I have are: W=12um, L=120nm, Av=3 V/V, Vdd=1.5V. I need to find Vgs but also I need to select the correct Rd to ...
1
vote
1answer
158 views

Why does the voltage gain of a transistor-based amplifier vary with input frequency?

Why does the gain of a MOSFET-based common-source amplifier depend on the frequency, and why does it vary the way it does? I did an experiment with a common source amplifier and recorded the gain ...
2
votes
1answer
71 views

Operational Amplifier gain bandwidth product

If the gain bandwidth product of an operational amplifier is a constant and |Vout/Vin| is also a constant does that mean that the operational amplifier will not function for all but 1 frequency? ...
0
votes
1answer
122 views

Audio Amplifier Design Questions

Consider the following system-level diagram of an AM receiver: I'm currently focusing on the baseband amplifier stage, which is used to amplify the audio signal. Its corresponding schematic is: ...
0
votes
0answers
29 views

Relationship between PNP Collector doping concentration and Voltage gain

For a PNP amplifier with \$ \large V_{in} \$ at base, and \$ \large V_{out} \$ at emitter, given that the voltage gain \$ \large A_v = \frac{-V_A}{V_T} \$, why does the voltage gain drops when the ...
0
votes
2answers
127 views

Gain and offset adjustment with voltage reference?

I am building an instrument that relies on a precision sensor module. The sensor is factory-calibrated, and outputs 0-10Vdc. I believe the factory calibration to be better than anything I can attain, ...
1
vote
1answer
93 views

analog automatic gain control design issue

I am trying to create automatic gain control circuit(AGC). I am newbie with not much experience Basically input to the 1st stage amplifier is form sensor based on that I want to control the gain of ...
4
votes
3answers
309 views

gain, bandwidth and GBWP of current to voltage converter with op-amp

It might be a silly question since I am new to circuits and have little knowledge about it. I've learned that gain of a current to voltage convertor with op-amp is determined by feedback resistor ...
1
vote
2answers
127 views

Hi-Fi Stereo Amplifier gain regulation with potentiometer

This is my first question ever so please don't kill me :) I have built a stereo hi-fi (end) amplifier 2x10W based on a IC TDA2009. I have bought it as a construction (learning) kit ready to solder. ...
0
votes
3answers
94 views

Transistor saturation

I am trying to saturate a transistor , a BC547 A , but I am having a hard time figuring out something.What hFE should I use to compute the base and collector current to make it turn on fully? Here is ...
0
votes
1answer
76 views

Small signal analysis of MOSFET. Calculating Gain

I can do DC analysis and draw the small signal equivalent circuit just fine. I generally have trouble calculating gain. I'm having trouble understanding the answer to this question. This is the ...
5
votes
3answers
287 views

Audio Amp-Calculate Current gain of a Push-Pull BJT Pair (and remove Beta Dependence)

I was designing an audio amp for a final project for an electronics course. We were given a very vague set of requirements and told almost nothing about our input signals or desired output minus ...
2
votes
4answers
172 views

JFET in place of digipot for gain control?

I'm hoping to build a sound sensor using this schematic (http://cdn.sparkfun.com/datasheets/Sensors/Sound/sound-detector.pdf) To programmatically adjust the gain, I could use a digipot. My (naive) ...
1
vote
1answer
464 views

Derivation of current gain and voltage gain for common base BJT

For a common base configuration BJT such as the one shown here: How can I derive the voltage gain and current gain?
0
votes
2answers
64 views

Finding the gain with a photodiode

How would I go about finding the gain of this circuit? Here's a link to the datasheet. Using our test apparatus to create a PWM on the diode, I get 1.16V out of pin 1. I can provide more information ...
0
votes
1answer
50 views

How to use a single supply with an opamp to create a DC amplifier

I have a single positive power supply, and I want to amplify a DC input signal. All sources I have seen decouple the input voltage with a capacitor because the input voltage is biased at VCC/2, ...
0
votes
4answers
147 views

Is the hfe of a transistor dependent on the resistance on the other parts of the circuit?

I have a circuit using a NPN transistor with a motor before it and a pwm into the base. The motors draws a current of 600mA if I plug it directly into the power source, just under the maximum allowed ...
1
vote
1answer
69 views

How do I tell if my amplifier is voltage-to-voltage, voltage-to-current, etc

I have an amplifier, which is essentially an amplifier and a motor driver in one (link to data sheet), and I'm having an embarrasingly hard time trying to figure out what/how much it is amplifying. I ...
0
votes
0answers
147 views

Understanding an op-amp LC tank circuit?

This is a circuit diagram for an op-amp LC tank circuit. I understand that the LC Tank circuit will decay unless some selective outside current is added, thus the op-amp. I'm simply having an ...
0
votes
2answers
66 views

The Gain reduce due to the input, Why?

I'm working with ICL7650S(online datasheet). Today, when I was working with the Op-Amp, I came across to an odd thing. this is my circuit: simulate this circuit – Schematic created using ...
0
votes
2answers
146 views

How to operate Op-Amp[OP07CP] with 0-5v supply?

I don't know why I cannot operate Op-Amps! this is my second circuit and I'm trying to make a non-inverting amplifier by an OP07CP. This is my circuit + an example of measured values: simulate ...
0
votes
2answers
213 views

Why Doesn't This Op Amp Preamp Circuit Amplify?

I have the following circuit as part of a class D amplifier: simulate this circuit – Schematic created using CircuitLab I couldn't get the amplitude of Vsig to display, it is ~.447Vp, to ...
1
vote
1answer
90 views

Differential gain of amplifier with current mirror

Consider this pdf document, pages 58-59-60. It is a differential amplifier with a current mirror as active load. According to that document, if I take the unbalanced output in the right-hand branch ...
0
votes
1answer
59 views

Equivalent impedance calculations from “both sides”

A circuit I have been working with lately consists of a binary counter being fed into an Op-Amp DAC, shown below. One of the major issues with this design is that the input impedance of the DAC will ...
0
votes
1answer
228 views

Determining DC gain of single supply op-amp (no AC component)

I'm building a homebrew PIC programmer, and want to support devices with varying Vpp voltages, so I'm using the DAC output of a PIC16F1825. But the PIC is supplied with a +5V Vdd, so that's the ...
1
vote
2answers
694 views

Why hFE(DC gain) shown on multimeter isn't equal to the datasheed hFE?

I have a tip122 and discovered my multimeter uses Vce=2,8V DC and Ib=10uA for its hFE test. When I insert the transistor on the terminals for hFE test, the gain on the multimeter alternates between 1 ...
0
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1answer
198 views

How to calculate the gain for a load cell to be used with instrumentation amp?

I was hoping someone can give me a step by step process for calculating the gain of my load cell.Here is the datasheet to it LoadCell datasheet. I also plan on using the INA125p instrumentation ...