Stats

  • Locked Locked
  • Replies 2
  • Subscribers 125
  • Views 14622
  • 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

xmax and xmin are returning nil

asetji

Hi,

I am trying to run xmax function on a derived signal, and even though I can see a clear maximum in the plot the xmax(z 1) is returning nil.

The circuit I am using is a simple LC tank driven by a voltage source and I am measuring current and I am using the following outputs

i = ifreq('ac "/V4/PLUS")

z = 1/i

now whether i use xmax(z 1) or xmax(z 0), both return nil which is strange because a maximum does exist. similarly running xmin also returns nil.

My main goal is to find the resonance frequency of the LC tank and then use sensitivity analysis to see how much it is sensitive to individual components.

values of the design variables are

ls=400p, Q=200K, Q_cap=1K, var_cap=100f,w=2*3.14*30e9

  • Andrew Beckett

    This is because the results from an ac analysis are complex, so there isn't a minimum or maximum value with complex data. Instead you'd need to use a modifier function (such as mag, db20, real, imag, phase etc) to convert the complex numbers at each frequency point to an appropriate scalar value for that frequency point. Probably what you want is xmax(mag(z)).

    Regards,

    Andrew.

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.