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Common-Emitter Amplifier Simulation

flux

6:53

Preparing a simulation.

Preparing for circuit modeling.

Evaluating measurement strategy.

Running Simulator.

Analyzing transistor phase.

Analyzing simulation data.

Running Simulator.

Clarifying data retrieval.

Considering waveform approximation.

Calculating values from snippets.

Examining AC phase behavior.

Evaluating voltage gain.

Clarifying CDN requirements.

Documenting simulation data.

Generating a plot visualization.

Clarifying the numerical output.

Simplifying waveform calculations.

Evaluating small-signal AC gain.

Simulation complete.

Calculating.

Common-Emitter Amplifier Simulation
Using the values exactly as you specified, I simulated the stage directly as a standalone theoretical circuit, which is the recommended flow for this kind of request . I also checked the result against the usual DC operating-point rule for BJTs: if VCE<0.3 VV_{CE} < 0.3 \text{ V}VCE​<0.3 V, the transistor is saturated rather than in the active amplifier region .
Plot
Image

Image

Results

MetricValue
Supply voltage12 V
Input10 mV amplitude, 1 kHz sine
DC base voltage728 mV
DC collector voltage48.9 mV
DC collector current11.95 mA
Collector output avg. (2-5 ms)50.7 mV
Collector output max63.37 mV
Collector output min41.58 mV
Collector output p-p21.79 mV
Input p-p20.00 mV
Voltage gain-1.0895 V/V
AC small-signal magnitude at 1 kHz0.960 V/V
Reported voltage gain
Using the transient amplitudes: Av=Vout,ppVin,pp=−21.79 mV20.00 mV=−1.0895A_v = \frac{V_{out,pp}}{V_{in,pp}} = \frac{-21.79 \text{ mV}}{20.00 \text{ mV}} = -1.0895Av​=Vin,pp​Vout,pp​​=20.00 mV−21.79 mV​=−1.0895
So the voltage gain is:
  • Gain = -1.09 V/V
  • Negative sign means the output is inverted, as expected for a common-emitter stage.
Important observation
This particular bias network does not bias the 2N2222 as a good linear amplifier. The collector sits at only 48.9 mV, so the transistor is deeply saturated, not in forward-active operation. That explains why the gain is only about -1.09 instead of a much larger negative value. That active-vs-saturated interpretation follows the standard DC operating-point check guidance .
If you want, I can next simulate a properly biased version of this same 2N2222 common-emitter amplifier and show how to get a much higher gain.
Bias it properly
Add emitter resistor
Run frequency sweep
26 days
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    555 Circuit rd1z

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    555 IC Turned Into A Clock Circuit. ( Astable )

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