Questions tagged [amplifier]
An amplifier can be used to adapt the range of a signal to a requirement, to make it more robust for transmission, or to satisfy interface requirements (like input/output impedance).
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Designing a circuit with a LM386 amplifier
I'm designing a circuit an I want to use the LM386 audio amplifier. Before designing, I'm going through the whole datasheet, I've seen that VI is from -0.4V to 0.4V :
Here is the first typical ...
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Which signal should be fed into the single ended input of the PAM8320?
I'm feeding audio from this DY-SV17F module into this PAM8320 amplifier.
The configurations I believe I can choose from are:
1: Feed either DACL or DACR from the module to the amplifier.
2: Combine ...
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100 kHz Class D Amplifier with out Transfomer
I have to design a class D power amplifier, able to deliver 200 W on 50 ohm load at 100 kHz.
Power supply should be 14 or 24V, I don't know at the moment so I need an output trasformer.
I did few ...
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How I can use light to control of amplifier?
I want to make a car that I can control by light, and I thought of using a photoresistor and a light sensor to control the amplifier to make it perform two functions.
The first function is to make the ...
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How to calculate an rf amplifier stage
I changed the LC tank of the circuit below for operation in the 2m ham radio band (144-146MHz, I'm a licenced Class A Ham). Now I'd like to add an amplifier stage to increase the output by about 30dB.
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Why am I getting this distortion in this circuit?
Can someone explain to me why I am getting this distortion for the following circuit? Input is a pure square wave. It happens at any input frequency or voltage. I was thinking the output would be a ...
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Can I make a simple distribution amp with a CD4050 hex buffer IC?
I've got a 555 circuit hooked up to a Stylophone-type keyboard. I'd like to duplicate the audio tones—which I assume are square waves (coming out of pin 3)—a couple of times and run them through an ...
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OpAmp Selection | Sine Wave Amplifier: 30 MHz, 30Vpp with 15V offset
I am currently working on amplifying the output sine wave of the TG5011 professional signal generator. Below are the specifications for the amplifier I am aiming to create:
Power Supply: A single ...
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RF connector selection
An antenna with its LNA has 3-7 V range for power supply for the LNA, and it’s written that connection is SMA for 3V, TNC for other levels. I wonder the main reason behind this. Can’t I use TNC for 3 ...
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Voltage gain of transistor amplifier [closed]
Given : Vs = 20sin(2π5000t)mV, RC =4.7k ohm, RE =1.2k ohm, R1 =100k ohm and R2 =22k ohm, such that the transistor is DC biased to IC =1mA and VCE =6V. (Here we use the method of I R1 = 10IB , and IR2 =...
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Max Power for a square wave on a breadboard
I am aware the max continuous power for a breadboard is 5 Watts. I am creating an amplifier circuit for a 1.7 MHz square wave using a mosfet. I would like to test it using a breadboard before I go ...
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Phenomena of antenna out-of-band mismatch effect on LNA
I m very confused about something and I wanna ask it by giving example. Let’s assume that an antenna has a frequency band of 1000 MHz to 1010 MHz with VSWR level 1.5 and impedance of 50 Ω, and uses a ...
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Suggestions for Improving this Pre-amp Circuit
I made this preamp circuit for a dynamic mic and am mostly happy with it, but I'd love to get suggestions on how to make it a little better. I'd like it to have as little coloration as possible, and ...
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How come negative power supply has negative voltage only
So I have seen power supplies that produce e.g. -48V DC (used e.g. in telecom but probably not only). For sure, that power supply is floating and in no way is negative terminal connected to earth. So, ...
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How can I bias the two transistors (Q59, Q58) two main transistors in my common emitter pnp amplifier? [duplicate]
[
I tried in my design to make a common emitter stage amplifier using a pnp transistor and a npn transistor as a current source but I didn't know to bias either of them (well as for Q54 I think I've ...
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How can I design a beta modulator block
I am simulating a block beta modulator, but the problem is to switch uses in that block. What component do I have to use in place of U3? I did not find this type of any component in LTspice library ...
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Why Am I Not Getting my Expected Output in this basic Op-Amp Circuit?
I thought that A = 1 + Rf/Ri for an op-amp non-inverting amplifier? With a 1mV input, I'm getting output voltages in the uVs...
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ThorLabs PC4QM Amplifier [closed]
I'm working with a Piezo Thorlabs PC4QM, 650nF 9.1um (150V), and I'm looking for a way to actuate (activate) it with a lower cost solution, such as developing an amplifier based on an existing chip, ...
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Understanding the working of the diode in opamps [closed]
I had seen one of the schematics where I found a diode in the feedback loop. The schematic is shown below, where I have two inputs from 0-5. I have the following questions about this:
What is the ...
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Voltage gain of this OPA circuit with AC input
The aim is to attenuate 10 times and cutoff frequency of at least 10 MHz.
I understood that the green section of the circuit reduces the voltage gain. I have noticed that increasing the orange section'...
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How to bias the Q55, Q54 transistors in my design (what's the right voltage value needed for it)?
I want to make a simple differential amplifier and when I bias the pnp transistor that's connected to Vcc I notice in simulation that the application is too small (less than 1) and it go around 4.96v ...
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Minimum hfe requirements
Is this the minimum voltage and current value for the said dc current gain.
Thanks
https://alltransistors.com/adv/pdfdatasheet_motorola/bc546_bc547_bc548.pdf
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Stability factor in BJT
I was wondering if the stability factor is a feature for all BJTs and does one need two resistors in a voltage divider emitter bias or a single resistor is enough?
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I am driving a LT3092 current source with a variable voltage - to get a variable DC current, but the output needs to float 0 to 1.5V above ground
What type of buffer amplifier would work - either discrete opamps or a differential output opamp? The output voltage would ideally vary up to 12VDC. The variable current source has a variable load ...
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BJT DC biasing and amplification
Does this part of the datasheet has to do with biasing and amplifying DC using BJT (TIP120)?
[!tip120 datasheet]2
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DC voltage amplifier circuit with up to 10kV output, up to 1mA
What components would I need for a circuit that would be able to magnify an input voltage in the 10s of volts at an appropriate wattage to produce an output voltage of up to 10kV at 1mA? I've read ...
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Why is a class A amplifier with load cooler than without load?
Why is a class A amplifier cooler with load than without load?
In a class A amplifier, the load is directly connected to collector section of transistor. What does 'without load' mean? Is the ...
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Multiple connections to power supply
My son and I are making an amplifier from a board from Amazon that requires 9-26 V DC input. I have an old laptop charger and am wondering if I can connect more ancillary boards such as input ...
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What is the purpose of this long capacitor/inductor chain on a DDS IC evaluation board?
Image of the B output stage of the EVAL-CN0304 AD9834 DDS Evaluation Board
IOUT_B is a current source, not potential source, so the initial say half of the circuit I get. The resistor gives us a ...
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AD9833 Function Generator Help
I'm looking to create an AD9833 function generator (and have been, for too long) and keep getting stuck on the hurdle of digital control. I'd like a good way to be able to vary frequency (easy enough),...
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Why is a transistor amplifier gain less than expected?
I'm trying to build a voltage amplifier using a transistor but am getting a lower gain than I expect.
The circuit I have is here:
simulate this circuit – Schematic created using CircuitLab
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LT1028 Vos trim value
I am using LT1028 in simulation from the datasheet shown below. Pin 1 and 8 are Vos TRIM.
Regarding Vos:
Vos is input offset voltage. In my LTSPICE simulation I didn't have in the model, I only had ...
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Are transistors on MMICs considered lumped elements?
Are transistors, in practice, always small enough to be considered lumped elements in Monolithic Microwave Integrated Circuits (MMICs)? Similarly for discrete transistors used in hybrid microwave ...
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Class AB amplifier sizing
I have simulated a class AB amplifier as shown in the attached diagram. Its working pretty fine at 5kHz and 500mV input signal.
However, the simulation fails when I try to change the requirements to ...
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Output impedance of class C amplifier
Question
How to calculate the output impedance of a class C amplifier, considering that maximum efficiency is a priority?
Explanation
I found two strategies:
The first strategy is to observe the ...
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Gate bias voltage in class C amplifier
Question
How should the gate of the MOSFET be biased to achieve maximum efficiency (in class c amplifier), when gain is not important?
Explanation
On the one hand, in the tutorial (link) it is shown ...
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Resonant circuit in class C amplifier
Questions
What is the better option when maximum efficiency of class C amplifier is needed:
LC circuit between VCC and drain of amplifier + low pass filter
RF choke and low pass filter
simulate ...
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Difference between the power and voltage amplifier?
What is the difference between the power and voltage amplifier?
Power amplifier (class A) amplifies the power while the voltage amplifier amplifies the voltage but problem is both are same circuit.
So ...
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What determines an electret microphone voltage?
I am trying to get an electret microphone working with my Raspberry Pi Pico's ADC pin. I am trying to detect the output by passing it through a transistor.
I have a 4.5V voltage source. I split this ...
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What's wrong in my amplifier circuit?
I am desinging a amplifier circuit. But the output is showing linear. please help.
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Multistage amplifier with frequency response
I am having a problem to analyze this amplifier all in one, I need a way to get into this.
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Where does power entering at the LNA's output go when output return loss and reverse isolation are so low?
I am looking at the QPA2609 amplifier's datasheet. I noticed that the Output Return Loss is about -20 dB at 13 GHz and the reverse isolation is around -60 dB at 13 GHz.
My understanding is that output ...
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Summing up transistor gains [closed]
I was wondering if its possible to sum up transistor gains.
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S parameters calculation from VNA file
I am trying to validate that our broadband LNA(Low noise amplifier) is working correctly. I wanted to measure the S21 of the LNA, I calibrated the VNA for the specified frequency range and measured ...
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Why does an electret not pick up sound?
I am trying to get an electret mic to detect sound, which I can then pick up using a Raspberry Pi Pico ADC pin.
My electret has two output pins. One is connected to ground, the other is connected to ...
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Class-d Amplifier board not working after capacitor is placed in parallel at dc input while running
Noob here. I did a dumb thing few days ago that destroyed my TPA3110 amplifier board which is running on 24V 15A Lithium battery pack with BMS.
I placed a 35V 4700uF capacitor across the 24V output of ...
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Output voltage thermocouple amplifier decrease when temperature increase
To detect surface temperature of heating foil, I decided to use thermocouple of type K. To amplify the small signal I choose the thermocouple amplifier with cold junction compensation integrated, ...
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Designing RC Coupled amplifier from bandwidth
Is it possible to design an RC Coupled BJT amplifier (finding resistor and capacitor values and constructing the circuit ) if only bandwidth is given? It is possible if cutoff frequency is given, but ...
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How to drive a darlington transistor like TIP120 to get high gain and high collector current?
simulate this circuit – Schematic created using CircuitLab
I'm trying to wire a darlington TIP120 just to see if I can get the 1000 hfe dc gain at 100mA like it said on the data sheet. I made ...
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