Home > Community > Forums > Custom IC Design > transient noise spectre

Email

* Required Fields

Recipients email * (separate multiple addresses with commas)

Your name *

Your email *

Message *

Contact Us

* Required Fields
First Name *

Last Name *

Email *

Company / Institution *

Comments: *

 transient noise spectre 

Last post Tue, Oct 23 2012 2:15 AM by soathana. 2 replies.
Started by soathana 18 Oct 2012 07:55 AM. Topic has 2 replies and 2539 views
Page 1 of 1 (3 items)
Sort Posts:
  • Thu, Oct 18 2012 7:55 AM

    • soathana
    • Top 500 Contributor
    • Joined on Fri, Jan 13 2012
    • Posts 24
    • Points 375
    transient noise spectre Reply

    Hi all.

    In transient analysis there is an option for taking into account noise. Which  noise components for a MOSFET are being taken into account (ie channel thermal, 1/f etc) or this is model dependent (ie BSIM4 noise parameters supplied). What exactly noise contibution is supposed to do? For example if in a resistanse i choose in generate noise->YES this gets overrided if i dont select it in noise contribution? Also in order to propagate noise over a path is it needed to select all components in path in noise contribution or not?

    Many thanks,

    Sotiris 

    • Post Points: 20
  • Thu, Oct 18 2012 8:27 AM

    Re: transient noise spectre Reply

    Hi Sotiris,

    This is covered in the documentation, and to some extent in "spectre -h tran". If you specify noisefmax (but not noisefmin), it will compute the noise spectral density at noisefmax and then treat the noise as white at all frequencies. If you specify noisefmin, then it will include coloured noise between noisefmin and noisefmax, and the noise spectral density (at source) will be computed using the model parameters (and so will include flicker noise) - and that will control the distribution of the random noise perturbation that the noise sources in that device will produce over time.

    Fundamentally the device itself needs to be generating noise - if you've turned off noise generation on the device with the "generate noise parameter on a resistor", then turning it on again in the transient noise won't help. The options on the transient noise to enable/disable particular contributors are just a way of refining the noise contributors - mainly filtering some out.

    There's no need to have all devices in a path to be producing noise for the noise to propagate - you can have a noisy source and then an ideal part of the circuit and the noise will propagate still.

    Does that help?

    Regards,

    Andrew.

    • Post Points: 20
  • Tue, Oct 23 2012 2:15 AM

    • soathana
    • Top 500 Contributor
    • Joined on Fri, Jan 13 2012
    • Posts 24
    • Points 375
    Re: transient noise spectre Reply
    Thanks Andrew. This was really helpfull.
     
    Sotiris 
    • Post Points: 5
Page 1 of 1 (3 items)
Sort Posts:
Started by soathana at 18 Oct 2012 07:55 AM. Topic has 2 replies.