The NOISE record may optionally contain text parameters:
T1, T2, T3, ...
where T1, T2, T3, ... are element names whose noises are to be included in the calculated output noise. If element names are not specified on the .NOISE record, then all circuit noise sources are included in the calculated output noise. If element names are included on the .NOISE record, then only the noise sources from the named elements are included in the noise calculation.
The .NOISE record may optionally contain two real number parameters:
F1, F2
where F1 and F2 define a noise bandwidth. If F1 is less than the starting frequency specified on the .AC record, F1 is reset to the starting frequency. If F2 is greater than the final frequency specified on the AC record, F2 is reset to the final frequency. If F1 and F2 are not specified on the .NOISE record, F1 is set to the starting frequency and F2 is set to the final frequency specified on the .AC record. The total integrated noise at the first requested output that results from the specified circuit elements is calculated and displayed as the second part of the noise result. At each frequency point in an .AC analysis, the integrated noise represents the total noise in a noise bandwidth between F1 and the current frequency point. The final result is duplicated at the termination of the AC analysis. The integrated noise calculation is done using the Trapezoidal rule [3] for numerical integration. It is up to the user to assure that the frequency steps taken are sufficiently small to assure accuracy.
Examples:
.NOISE * ask for total circuit noise density at first
* requested output.
* Also provides total noise from all circuit
* elements between F1 and F2 specified on .AC record.
.NOISE r3, amp1 * noise from circuit elements r3 and amp1 only.
.NOISE r44 120. 3000. * integrated noise between 120. and
* 3000. Hz (or rps) from r44.