Questions tagged [class-a]
For questions about class A amplifiers, in which the active element conducts all of the time. Other amplifier classes include B, AB, and C-H. Compared to other amplifier classes, class A amplifiers are the simplest and have no crossover distortion, but are the least efficient. Consider using this tag in conjunction with the "transistors" tag.
48 questions
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Class A Amplifier - Theory v. Simulation
I am trying to compare theoretical results with the simulation of the following amplifier.
The respective values are
$$V_\mathrm{CC} = 12\,\text{V}, R_\mathrm{B} = 470\,\text{k}\Omega, R_\mathrm{C} = ...
- 193
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1
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Offset and Miller compensation
I'm currently training for analog design and my co-worker is teaching me step by step on how to do the design. I'm designing a Class A amplifier. So for the differential pair, I have 80 uA tail ...
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2
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1
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Confusion when Deriving Class A Amplifier Efficiency
I am currently taking an RF amplifier course at a university and I am having trouble understanding the derivation of efficiency for a class A amplifier. I understand the derivation pretty well for the ...
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2
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Should Vce or Vc be set to half Vcc when setting the Q_point of an NPN BJT?
In a "class A" NPN BJT transistor amplifier, in determining the Q-point I am used to setting Vce equal to Vcc of the circuit. I do that as I heard "to give more headroom for the signal ...
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2
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Best Technique to Find 'The' BJT For Your Circuit?
I'm working on a small high voltage cascode stack class A amplifier. The bandwidth is primarily limited by BJT capacitance. I have a working prototype, as well as a well defined LTSpice simulation.
My ...
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Measured gain 10x higher than calculated gain - common source amplifier
I have a pretty basic common-source amplifier, using a 2n7000 nmos transistor. Gate bias is set with two resistors to give Vgg = 4.83V. Rd = 555.7Ohm and Rs = 218.8Ohm. There is a bypass capacitor ...
1
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1
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In a class A amplifier using a (BJT voltage divider bias) with no transformer coupling, how can one calculate the input DC current? [closed]
In a class A amplifier (using a BJT voltage divider bias) with no transformer coupling, how can one calculate the input DC current? The current drawn from the supply is ICQ (which flows in the ...
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2
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190
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Question about class A amplifiers
I am trying to understand the working principle of a simple class A amplifier.
Below you can find a diagram of the inner components.
I am struggling to understand why the gain \$G\$ is given by the ...
2
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5
answers
959
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Stages of audio amplification from mV to 20V+
I have been trying to learn how to amplify audio signals from very small signals (20mV) to large signals (20V+) while using only transistors. I have figured out how to build a class A common emitter ...
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3
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Need help with audio amplifier design for loud volume
I'm trying to design an audio amplifier. The preamp stage is a voltage divider CE, while the power stage is a Darlington Class A:
My goal is to amplify a \$48.7\ \mathrm{mV},\ 1.07\ \mathrm{mA}\$ (...
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Audio Class A amplifier [closed]
Currently I am trying to copy the class A amplifier using the following components:
1k ohms Resistor, 10k ohms resistor, 470 ohms, 50k ohms Resistor, 2n3904 bjt transistor, 10 uF capacitor. With a ...
0
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2
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Power Amplifier Class A
I have tried using 2 method but I'm getting different answers in both methods.
in the first case I assumed Vce=Vcc/2 and Vcc-IcRc=Vce
For maximum power transfer Vcc/(2√2)×Icc/(2√2)=Vcc×Icc/8=20W
Vcc/2=...
user351581
2
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4
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Drawbacks of Class A push pull audio power amplifier?
I am willing to develop an Audio power Amplifier myself in a Push Pull configuration of two complementary transistors (NPN,PNP).
On the internet, it is found that most of the conventional Class AB ...
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4
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What went wrong with this class A amplifier design?
I was trying to build a normal class A amplifier, but no matter how hard I try, I cannot find the reason behind my output (blue line) being clipped at the negative cycle of the input (yellow line.)
...
- 43
0
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0
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RF amplifier class A
I have simulated a class A RF amplifier. When I simulated the output impedance, it is around 50 Ω for the frequency range that is of interest (50 kHz to 100 MHz), now at the input impedance is around ...
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