PSRR of a VCO using spectre-RF?

Discussion in 'Cadence' started by rachelms79, Dec 23, 2004.

  1. rachelms79

    rachelms79 Guest

    Is there a way to simulate the PSRR of a VCO using spectre-RF? I want
    to plot the delta-frequency of the VCO vs. the input frequency of a
    sinusoidal tone on the power supply. It seems PXF can give me the
    delta-voltage of the VCO output vs. the frequency of the tone on the
    power supply, but not the delta-frequency. The true brute-force method
    would be to run several transient sims of the VCO each with a different
    frequency tone on the supply (e.g. 1MHz - but this would take 1us of
    sim time to see one cycle of the tone! and the VCO is at 5GHz.)
    Any ideas? thanks.
    rachelms79, Dec 23, 2004
  2. I think you could probably do this using the "modulated" option on the PXF
    analysis introduced in IC5033 and later.

    This allows you to look at the AM and PM component of the transfer function.

    I _think_ that ought to do it, but not 100% sure without thinking about it a
    bit more...

    Andrew Beckett, Jan 26, 2005
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.