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AR# 42024

MIG 7 Series DDR3 - What is the recommended trace impedance between the FPGA and the DDR3 SDRAM?


Does Xilinx specify the recommended trace impedance between the FPGA and the DDR3 SDRAM for the MIG 7 Series DDR3 design?

NOTE: This answer record is a part of the Xilinx MIG Solution Center (Xilinx Answer 34243) 

The Xilinx MIG Solution Center is available to address all questions related to MIG. 

Whether you are starting a new design with MIG or troubleshooting a problem, use the MIG Solution Center to guide you to the right information.


Xilinx recommends 40 ohm traces for DDR3 SDRAM memory interfaces running at or above 1333 Mb/s. 

40 ohm traces provide better SSI and signal integrity because they can transfer more energy to the receiver at the SDRAM.

50 ohm traces can be used for slower data rates.

The 7 Series FPGAs Memory Interface Solutions User Guide (UG586) now documents these recommended trace impedances. 

Please refer to the user guide for additional information.

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AR# 42024
Date Created 05/03/2011
Last Updated 06/23/2014
Status Active
Type Solution Center
  • Kintex-7
  • Virtex-7
  • MIG 7 Series