Model Operational Amplifier with Noise

This example shows how to incorporate noise into an electrical simulation. The circuit models an amplifier with a high-frequency roll off frequency of 10MHz. The Band-Limited Op-Amp block adds the noise. The Voltage Source block, Vn, specifies an equivalent voltage noise density of 20 nV/Hz^0.5. You can also add the thermal noise from the resistors R1 and R2 by setting the Noise mode parameter of the two Resistor blocks to Enabled. However, running this model with different combinations of noise sources shows that the main source of noise is the equivalent noise voltage.

Open Model

View Simulation Results from Spectrum Analyzer