Intel manual Intel 31244 PCI-X to Serial ATA Controller

Intel® 31244 PCI-X to Serial ATA Controller

Routing Guidelines

For a symmetric trace Z11 = Z22, the differential impedance may be calculated from this equation:

Zdifferential = 2(Z11-Z12)

For two traces to be symmetric, they must have the same width, thickness and height above the ground plane.1 With the traces terminated with the appropriate differential, impedance ringing is minimized.

1.“Terminating Differential Signals on PCBs”, Steve Kaufer and Kelee Crisafulli, Printed Circuit Design, March 1999

30 Design Guide