Spice3f5

Resistor noise

The thermal noise of a 1kΩ resistor, to check against the expected value.

A 1kΩ resistor driven by a current source. The output noise spectral density should be 4kTR = 1.657575e-17 V²/Hz at 27°C, the value the deck's comment gives.

Output

onoise_spectrum = 1.657575e-17

The circuit: examples/resnoise.cir

simple resistor circuit
* simple resistor circuit to test which ones of vspice, uf77spice and
* spice3 give the correct results (1.657575e-17)

iin 1 0 1m AC
rl 1 0 1k

.control
noise v(1) iin dec 1 1k 1k 1
print onoise_spectrum
.endc

* for e.g. xyce
*.noise v(1) iin dec 1 1k 1k 1
*.print noise 

.end

Run it with spice resnoise.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