3 Replies Latest reply on Sep 26, 2018 7:51 AM by weston_beal

    Decoupling Wizard in Linesim

    louise

      Can the decoupling wizard in Linesim be used to predict the pre-layout target impedance of a PDN?

       

      What has been your experience?

       

      Thank you.

        • 1. Re: Decoupling Wizard in Linesim
          weston_beal

          Rajan,

           

          The term Target Impedance usually means the maximum impedance that an IC vendor expects to measure at the IC power pins. It's the goal. On the other hand, the decoupling wizard analyzes a layout to determine the actual impedance over a frequency range. If we change your question just a little bit to, "can the decoupling wizard predict pre-layout impedance of a PDN?", then the answer is yes. The Target Impedance should be calculated from the IC characteristics or specified by the IC vendor.

           

          Regards,

          Weston

          • 2. Re: Decoupling Wizard in Linesim
            louise

            Hi Weston,

             

             

             

            Thank you for your reply.

             

             

             

            I agree with your terminology and that Ztarget is calculated from specific

            IC characteristics

             

            such as tolerable ripple levels etc ...

             

             

             

            Have you used the Decoupling Wizard to analyse a PDN schematic entered

            within Linesim

             

            to determine its actual, pre-layout impedance vs. frequency?

             

             

             

            Kind Regards,

             

            Rajan.

            • 3. Re: Decoupling Wizard in Linesim
              weston_beal

              Rajan,

               

              It is reasonable to analyze a preliminary PDN in LineSim. I suggest some practice with the editor on very simple to increasing complexity designs to see how the editor works. Just be careful with the assumption of how closely the result of the preliminary PDN represents the actual design. The actual design always has more holes and cuts that diminish the performance of the PDN.

               

              Regards,

              Weston