BJT noise

Noise analysis of a common-emitter amplifier.

A common-emitter amplifier with a flicker noise coefficient on the transistor. The noise analysis makes two plots: the noise spectral densities, and the noise integrated over the frequency range.

The circuit: examples/bjtnoise.cir

BJT Noise Test
*
vcc 4 0 50.0
vin 1 0 dc 0 ac 1
ccouple 1 2 1
ibias 0 2 100uA
rload 4 3 1k
q1 3 2 0 0 test
*
.model test npn kf=1e-20 af=1 bf=100 rb=10
.control
noise v(3) vin dec 10 10 100k 1
* noise generates 2 plots:
*	noise1: noise spectral density
*	noise2: integrated noise
*
setplot noise1
plot v(onoise_spectrum)
.endc
.end

Run it with spice bjtnoise.cir, or open it with File › Load netlist in the Qt window. The plots and output above were made by util/mkexamples.py, which runs the deck in batch mode. All examples