When performing a noise analysis in LTspice of a 1kΩ resistor, a noise level of 4nV/rtHz is simulated.
However, if this resistor value is set to 1kΩ using
.param, its noise decreases to 129fV/rtHz. Changing this resistor value does change the noise linearly. What causes this noise decrease, and what can I do to prevent it?
The schematic is shown below: