Issue link: https://resources.pcb.cadence.com/i/1180526
PSpice User Guide AC analyses October 2019 502 Product Version 17.4-2019 © 1999-2019 All Rights Reserved. What is noise analysis? When running a noise analysis, PSpice calculates and reports the following for each frequency specified for the AC Sweep/Noise analysis: ■ Device noise, which is the noise contribution propagated to the specified output net from every resistor and semiconductor device in the circuit; for semiconductor devices, the device noise is also broken down into constituent noise contributions where applicable Example: Diodes have separate noise contributions from thermal, shot, and flicker noise. ■ Total output and equivalent input noise How PSpice calculates total output and input noise To calculate total noise at an output net, PSpice computes the RMS sum of the noise propagated to the net by all noise-generating devices in the circuit. To calculate the equivalent input noise, PSpice then divides total output noise by the gain from the input source to the output net. This results in the amount of noise which, if injected at the input source into a noiseless circuit, would produce the total noise originally calculated for the output net. Table 10-6 This value... Means this... Output noise RMS sum of all the device contributions propagated to a specified output net Input noise equivalent noise that would be needed at the input source to generate the calculated output noise in an ideal (noiseless) circuit