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 Transient convergence issue 

Last post Mon, Jun 18 2012 6:30 AM by h1jo2d3put4. 2 replies.
Started by h1jo2d3put4 25 May 2012 04:58 AM. Topic has 2 replies and 3198 views
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  • Fri, May 25 2012 4:58 AM

    Transient convergence issue Reply

     Hello everyone,

    I'm new in this forum and a newbie using cadence. I've been trying to simulate an oscillator circuit using transient, but the simulation never converged. I started reducing the size of the circuit until I ended up with circuit shown in the picture attached. It is actually a transient simulation with all the default parameters with a simulation time of 1 ns. The simulation crashes after a few fs for the liberal or conservative error setting and takes ages to run until it eventually crashes for the moderate option. 

    Any comments and/or suggestions will be much appreciated.

     Regards,

     


    • Post Points: 20
  • Wed, Jun 6 2012 6:11 AM

    Re: Transient convergence issue Reply

    I tried constructing the same circuit and it didn't "crash" for me (I assume you meant it stopped with the blow up error you showed in your image, rather than crashing) - but I was having to guess what some of the parameters are. Best to post the input.scs .

    However, I guess your circuit does not really have a 1 Farad capacitor in it? Large ideal component values can be problematic... I suspect the circuit is unstable (maybe try running a pz analysis to look for RHP poles).

    Andew.

    • Post Points: 20
  • Mon, Jun 18 2012 6:30 AM

    Re: Transient convergence issue Reply

     Thank you very much for your answer. Following your advice, I reduced the capacitances and the simulation started to converge.

     

    Regards,

    • Post Points: 5
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Started by h1jo2d3put4 at 25 May 2012 04:58 AM. Topic has 2 replies.