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Questions tagged [amplifier]

An amplifier can be used to adapt the range of the signal to a requirement, to make it more robust for transmission, or to satisfy interface requirement (like input/output impedance)

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2answers
74 views

Stk086 distance between pins? [closed]

I have been trying to make a footprint for this IC, and trying to figure out the distance between pins, it is a 10 pin ic what do you think the distance will be? What is the normal distance between ...
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0answers
47 views

Differential Amplifier Exam Problem

I am lost with how to approach part C and D of the question. In fact, I need some intuition with how to tune a differential amplifier.
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0answers
52 views

Portable Guitar Amp - Distortion, Volume & GND

I have tried following the given schematic There are 3 things I am unsure of (what I tried): The Volume 5k Potentiometer: I have tried adding a volume control to the schematic by placing the ...
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1answer
66 views

How to amplify current and buffer voltage

I have a battery supplying 5V@500mAh and an LED (the load) which draws 1000mA@5V (twice the current the battery supplies per hour). I found some circuits that have NPN transistors only and other ...
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2answers
50 views

Amplifier advice for speech sythesizer circuit

I'm designing a circuit that hooks up an SP0256A speech synthesizer to an AVR microcontroller and would like some help with the audio output amplification. The datasheet describes the output as being "...
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2answers
79 views

Audio amplifier for 600 ohm headphones

I am working on a design which must drive an audio output into 600 ohm headphones (aviation headsets). Normally, I would just use an off-the-shelf class D amplifier but I can only find ICs designed to ...
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1answer
44 views

MOSFET Differential Amplifier voltages via PSpice and by hand

I want to do an analysis on a differential pair and there is a problem when the pair is in common-mode, at least that's what PSpice says. I find that \$V_{DS}\$ of both MOSFETs is 1.1V and PSpice ...
4
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1answer
210 views

How do I appropriately power a headphone amplifier and where do I place the volume regulating potentiometers?

At the moment I am building a device that splits an analog stereo audio signal into 3 signals and amplifies 2 signals for headphones. I need to know how to supply -12VDC and where to put the volume ...
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1answer
49 views

2-stage BJT CC-EC amplifier [closed]

Using proteus I designed this amplifier: But I got this result: I don't know what is the problem in my design. I've been changing the values of the linking capacitors but didn't get any result.
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1answer
46 views

BJT LT spice DC transfer characteristic

Why is it that the DC transfer characteristic isn't flattening out at -5 v, so it looks like a Z-shape? I did a DC sweep from -10 V to +10 V. The input wave is a 2V sine wave for the graph below:
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1answer
65 views

Need help with three-stage transistor amplifier in LTSpice

I am currently attempting to design an amplifier in LTSpice for an E1 project. My professor tends to emphasize analysis of these circuits, so he hasn't really given us any kind of a design process to ...
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1answer
55 views

OP amp Comparator not working any tips?

I´m running out of ideas here. I have a device that should always output a 5v signal, with a maximum tolerance of 100 mV (4.95 to 5.05 V). I´m building a "tester" device. My tester will compare the ...
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0answers
57 views

Missing resistors vaules

A question for some guys is simple, but it is not for me. I am having difficulties finding the right formula to calculate resistors value or voltage drop across R1 through R8. Does anyone have an ...
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1answer
32 views

Looking for a small comparators which do compare a input [closed]

and output when reach the set value。  Or can anyone tell a simple circuit to build one.
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2answers
77 views

Why my non-inverted amplifier does not work?

I'm trying to use a TL081, for which I used a DC power supply regulated by MPL1303, to feed the TL081 and a Vin from a DAQ assistant giving an analog signal of 0 to 5 V. I tested the signal from the ...
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1answer
92 views

Transistor current amplifier circuit

I'm trying to make a circuit that has a load resistance of 2 Ohms, load current draw of 2A and voltage of 5V. The circuit can only be fed with a 5V@500mAh battery. Here is a diagram I have thought ...
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1answer
29 views

Class a amplifier load capacitance

What would happen in a class a amplifier if I connect a capacitor in series with the load resistor (between power supply and the transistor collector)? My goal was to block the dc qiescent current to ...
1
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1answer
113 views

Op-amp problem, two inverting amplifiers?

So I stumbled across a rather strange ideal op-amp circuit that I've never encountered before. I've done enough problems regarding inverting amplifiers, non-inverting, summing, difference, and such, ...
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2answers
68 views

Current sense amplifier

I came across this circuit for a high-side current sense using BJT current mirror, and I am trying to derive a formula for how I could calculate the sense voltage output (going to the FB pin) in terms ...
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2answers
84 views

Is my amplifier correct?

My goal was to amplify audio signal coming from Raspberry PI's audio jack, so it is louder. I have basically no clue what I am doing, but it seems to work - when I connect the speaker directly to the ...
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0answers
23 views

Operation of Swing-Type Voltage Controlled Amplifier

I'm trying to understand this Swing-Type Voltage Controlled Amplifier which is found in the classic Roland TR-808 drum machine. What I understand currently is that the input signal to the base of the ...
0
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1answer
67 views

Class-AB Amplifier Excessive Heat

I'm using a TI TPA6017A2 as a pre-amp for an in-car audio application and it's getting excessively hot, to the point where the IC burns my finger when touched if I set the input volume to max. Beyond ...
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0answers
76 views

Extending the negative rail range for an Op Amp

I'm building a Transimpedance amplifier using the ADA4530-1 op amp by Analog Devices. I'm attempting to sense a fA current signal that is always negative and I would like to see if it would be ...
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2answers
57 views

Amplifier MOSFET (25m - 5V)

I dont know how to amplify a signal of 25mV to 5V amplitud signal ((frequency of audio input cell phone)). I have this circuit so far:
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2answers
74 views

Not getting an ac current output through my speaker in my amplifier circuit

Will the dc current output affect the speaker, and prevent it from functioning properly? I have already tried different capacitors also change the input voltages and frequencies. I would really ...
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1answer
144 views

when a diode is forwards biased can current flow backwards through it?

when a diode is forwards biased can current flow backwards through it? this question comes from me trying to understand class AB amplifier biasing, so any additional comments about the diodes' use ...
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0answers
35 views

How do I design a MOSFET based amplifier with constraints

I am designing an amplifier using two MOSFET stages. The input is taken from a sensor and is to be amplified by a factor of 25. The output (of these two transistors) will be fed to a detector with a ...
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1answer
32 views

Matching Networks on Narrowband Multistage Low Noise Amplifier (LNA)

How does the inter-stage matching network of a narrowband LNA compare to that of a wideband LNA for the same multistage design? I've read somewhere that narrowband LNA does not necessarily require a ...
2
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1answer
71 views

Reasoning behind values of CE amplifier

I have the following circuit: I am asked to choose values for the different components such that at the end, the amplifier meets certain requirements. In the solutions, I am told that to minimise ...
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3answers
131 views

Is a bigger resistor different from a smaller resistor with same color stripes?

I changed a resistor with same color stripes Yellow, Purple, Gold, Gold on a Pioneer surround system but the only difference was that the I put was a bit bigger. The problem is the system went into ...
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1answer
39 views

Cascading an Op Amp at a desired frequency question

So I have a lab practical with the instructions "Demonstrate an operational amplifier circuit which may consist of one or two op amps with a gain of X (±10%) and a -3dB frequency exceeding Y kHz. The ...
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0answers
24 views

Can I choose the 18W amp for my 1" tweeter (50 W AES Power Handling)

I have a question - I want to take a 18W TDA2030A amplifier kit to power my tweeter in my PA system. I have an active crossover in it, that's why I have separate amp for each driver. My tweeter is 1" ...
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0answers
18 views

Common Source with Active Load

I'm trying to design this circuit using gm/Id method. I am already able to achieve the desired GBWP and Gain (this is just a simple example so I'm just trying to achieve both) but I'm having trouble ...
0
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1answer
75 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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1answer
26 views

Common Mode Voltage Range with Negative Feedback

In section 3.1 of AN21 from Apex Microtechnology it mentions to make sure to accomodate the common mode voltage requirements. But does the common mode voltage range mean anything if one of the inputs ...
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1answer
121 views

Class C amplifier low wattage

I am an EE student and my final project was giving to us without explaining what power amplifier are or how to design them. After researching and working on designs for about 40+ hours, I have come up ...
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3answers
84 views

Amplifying high frequency AC using op-amp or alternative methods

Right now, for my project, I am trying to design a circuit for generating 10 kHz to 1 MHz AC signal with ~80 Vpp to 100 Vpp. Currently, I chose to the AD9850 chip for generating AC with Vpp being ...
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2answers
57 views

Mathematical model for differential signals and relation with reality

i have a question and i hope is not that strange. i spend some time asking myself how people came out with the mathematical model for differential signals and why is this better in this way?! to be ...
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0answers
33 views

Can I get help identifying this NTC Thermistor

I found this thermistor blown, I’d like to replace it, but can’t seem to narrow it down
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0answers
33 views

Using Digital Amplifier Daughter board in SONY Port Replicator Dock

I have a useless Sony port replicator model vgp-prav1, that has a digital amplifier board as in attached picture. I would like to ask if is it possible to use this amplifier externally? as far as ...
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1answer
59 views

Q: Need help designing Pre-Amplifier

I am trying to design a pre-amplifier before going into a power amplifier. I essentially just want to signal condition a little more before the power amplifier. Whats really confusing me is the input/...
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1answer
56 views

Hello, this is not my circuit. but I'm playing with it, and I have some questions

hello. First, this is not my circuit. Second, I'm newbie student. I just started studying electronic circuit two weeks ago. I'm just playing with this Circuit. just poking around.. I have some ...
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0answers
30 views

Register description of TFA9896

I'm looking for the register description of TFA9896. Unfortunately, the datasheet doesn't contain these information: https://www.nxp.com/docs/en/data-sheet/TFA9896_SDS.pdf Do you know where to find ...
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0answers
58 views

Choosing the right amplification/gain for the internal PGA of an ADC IC

Problem I need to read a sensor (multiple of the same kind) with a microcontroller. The sensor I have, outputs a signal in the range of 0mV up to 20mV. Thus, it needs to be amplified and send to an ...
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1answer
48 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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1answer
89 views

RF Development board layout questions

I was looking at the development board layout for the MMZ09312B and I had a few questions: datasheet: http://cache.freescale.com/files/rf_if/doc/data_sheet/MMZ09312B.pdf Are large polygon pours away ...
0
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1answer
37 views

Diode on op-amp output to drive tube

I am working on a tube based guitar amplifier, and found an interesting schematic online. There is an op-amp that has diodes across a resistor in the feedback path. I understand what it makes the op-...
0
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1answer
45 views

Choosing transistor for amplifier

I'm going to design amplifier, requirement is that impedance for in should be more than 20kohm, impedance for out should be less than 50ohm, and voltage gain should be more than 200. So I'll make cc-...
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0answers
16 views

Created this Filter Amplifier Circuit; How do I connect this load while maximizing gain?

*Filter Circuit on Left, Load on Right. To give some background, that load is supposed to replicate a long 12V power line (with other stuff on it) on which we will be sending AC signals on. The gain ...
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1answer
52 views

Buffer with TL084CN and resistors

simulate this circuit – Schematic created using CircuitLab There are two buffers made with the TL084CN, which is part of the conditioning of an LTS25-P transformer. Currently, I have put a ...