AnsweredAssumed Answered

SI simulation differs with real measurement a lot

Question asked by on Jun 22, 2015
Latest reply on Jul 20, 2015 by matthias.cosaert

Hi Sir,


I am a beginner of Hyperlynx, try to do SI simulation as a reference for my next version of PCB design.


On my current PCB, there are 64 LVDS interfaces, all running at maximum 960Mbps, from eight ADC (ADI AD9279) to a FPGA (Xilinx Virtex-6).


Below is real measurement of one of the LVDS interface ( at 250Mbps, at FPGA side ) :



And below is SI simulation result from Hyperlynx,

as you can see, simulation result is totally different from the real measurement.


stimulus setting as below :


simulation trace :



On the other hand, we had previously assign a 3rd party company to perform SI simulation on these LVDS traces, below are two of the results :


at 480Mbps :



at 960Mbps :



They use exactly the same IBIS models of mine in Hyperlynx(also attached in this post), so I do think my problem is related to parameter setting in Hyperlynx (?).


Any comment is appreciated, thanks in advance.