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FUJITSU SEMICONDUCTOR CONFIDENTIAL
MB86R12 Application Note
DDR3 Interface PCB
Design Guideline
4.5.
Wiring gap/Crosstalk
Please keep to the wiring configurations shown below in order to avoid malfunctions and deteriorated
signal integrity due to crosstalk.
(1) The recommended gap for wiring within MDQx_Group and MCMD_Group groups should be over
300µm.
Figure 4-2 Gap for wiring within MDQx_Group and MCMD_Group
(2) The gap for wiring with other groups should be over 300µm.
Figure 4-3 Gap for wiring of other signal groups
(3) Differential wiring signals of MCK_Group and MDQSx_Group should use a wiring gap of over 500µm
to other signals.
If it is difficult to guarantee a gap above 500µm, separate the wire from other signals using a GND area.
However, please take the consequent decrease of the wiring impedance into consideration.
Figure 4-4 Gap for wiring between signal in MCK_Group/MDQSx_Group and other signals
MA1
Over
300μm
MA0
Example:
MDQ1
Over
300μm
MDQ0
Example:
MDQ8
Over
300μm
MDQ0
Example:
MA0
Over
300μm
MDQ0
Example:
Other signals
Over 5
00μm
MDQS0
Example:
Other signals
Over 5
00μm
MCK
Example:
