Stats

  • Locked Locked
  • Replies 5
  • Subscribers 126
  • Views 2838
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

What is the purpose/function of having multiple Noise/Fred pairs in independent sources?

delgsy

The picture below is the setup I am using.
I am trying to find the rms noise at VOUT from transient noise simulation and got the same result regardless of the number of Noise/Pair.
From here, I conclude they are white noise. If it is so, why is it possible to have multiple pairs? What is the purpose?

If there is any reference about this, I would like to know.

I cannot find any information in Spectre/Analog Library Reference.


Parents

  • The noise can be coloured (it doesn't have to just be white noise) - which is why you can specify multiple noise/frequency points. It's also used in noise analysis as well as transient noise.

    The best thing would be if you could share the input.scs from the two examples - so I can see the setup, the values, and the analysis statements. Then I can probably tell more easily what's right and what's wrong.

    Regards,

    Andrew

  • in reply to Andrew Beckett

    Hello Andrew,

    In my earlier reply, I used more than one Noise/Freq pair with the same noise value.
    I checked the noise spectrum and they are just the same because the noise value is the same.
    So it is quite acceptable if the rms noise voltage at the capacitor is the same.

    Later I made several other simulations.
    The picture below summarizes the result.
    There are some other things which I do not understand here.
    But here is the first one.
    In the top left, 4 simulations have different total noise, but they have exactly the same rms noise voltage.
    From the computational/software point of view, is this valid?

    If there is any reference about this kind of simulation, I would also like to know.

Reply
  • in reply to Andrew Beckett

    Hello Andrew,

    In my earlier reply, I used more than one Noise/Freq pair with the same noise value.
    I checked the noise spectrum and they are just the same because the noise value is the same.
    So it is quite acceptable if the rms noise voltage at the capacitor is the same.

    Later I made several other simulations.
    The picture below summarizes the result.
    There are some other things which I do not understand here.
    But here is the first one.
    In the top left, 4 simulations have different total noise, but they have exactly the same rms noise voltage.
    From the computational/software point of view, is this valid?

    If there is any reference about this kind of simulation, I would also like to know.

Children
No Data

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.