Questions tagged [common-emitter]
A common emitter is one of three basic bipolar junction transistor (BJT) amplifier topologies. It is notorious for a high power gain. It is the only one-stage BJT amplifier topology that permits gain both in voltage and current.
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Determining the zeros and poles of a common emitter amplifier
I want to determine the transfer function of the base common emitter amplifier. I don't want to neglect the impedances of the capacitors in the calculations because I want to determine the zeros and ...
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Why should the Vce be half the value of the supply source?
For a BJT amplifier biased to operate in the active region; I think that the statement "the voltage Vce is half the value of the supply source" is incorrect. Because I know that such a thing ...
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Do transistors "prefer" to pull current from their base or collector?
The circuit below is a simple BJT amplifier which behaves exactly as expected:
If I remove the capacitive coupling and voltage divider bias and replace it with an input offset, it completely breaks ...
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Why does the voltage increase when I connect this amplifier to a gate driver?
I'm trying to breadboard a simple circuit testing a TI UC3708N gate driver, which I need to drive from an AWG square wave. Since the AWG has limited amplitude (and perhaps limited current), I made ...
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How to analyze common-emitter amplifier by reflecting base impedance to emitter?
In chapter 2 of Dr. Middlebrook's video series Technical Therapy for Analog Circuit Designers he gives 2 examples of how solving a CE amplifier by "doing the algebra on the circuit diagram" ...
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BFU730F doesn't work on real experiment, what is wrong?
I have calculated BFU730F transistor on paper - all is ok.
I have created simulation for similar transistor (BFR740 because there is no BFR730) - all is ok.
I have maked shematics - it is not working. ...
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Is the resistor between the clock and the NPN needed?
I have a circuit that uses an NPN transistor inverter to invert a clock signal. The circuit calls for two resistors, a pull up and one in between the input signal. Virtually all of the circuits found ...
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Is LTspice AC analysis trustworthy at RF when using low impedance sources?
I'm an amateur at circuit design but I've been reading a lot and trying my best. I've edited the question to try to make the main problem more coherent and add a simple schematic and plots.
My setup ...
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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 ...
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Breaking "rule of thumb" for common emitter?
I'm trying to understand this common emitter amplifier that is part of the of a guitar pedal. The image is take from the ElectroSmash analysis from the Big Muff Pi .
The values for R6 and R4 are ...
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LTspice: Troubleshooting a common emitter amplifier
This is a screenshot of a common emitter amplifier my instructor made in LTspice (everything is working fine):
This is my attempt to make the same circuit (it isn't working, there's no amplification ...
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PNP transistor not pulling up completely : what is wrong in my schematic?
I cannot seem to make the schematic below work.
As you will plainly see, the idea is to use the PNP as a switching device for a PhotoMOS (TLP354x).
By switching SW1, Q1's base goes to the ground ...
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Emitter circuit on a breadboard
I am working on an emitter circuit that has a 2N3904 NPN transistor.
I have simulated the circuit before and got the results. I am trying to build it in the lab so I can compare the results to my ...
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No DC offset observed in the CE amplifier circuit part
The objective is to make an audio amplifier. We have decided to make one that has four stages: a pre-amp with a gain of around 120, the next one is a CE amplifier with a gain of around 5, the third ...
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Why am I concluding that the emitter-degenerated CE stage is unilateral?
Consider the attached small-signal diagram for an emitter-degenerated CE stage:
It's been a long day so I must be making an error, but I continue to conclude that this two-port is unilateral (defined ...
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