Figure 11-16: Simulated Phase Response Of 45 Degree Bends With Jog-Outs - Xilinx Virtex-4 RocketIO User Manual

Chapter 11: Design of Transitions
Figure 11-16
jog-outs and plane cutouts.
Figure 11-17
four pairs of 45° turns — i.e., four 90° mitered turns in each structure.
The left side of
P/N mismatch of about 33 ps of down-and-back delay from the structure without the jog-
outs. The P/N mismatch is one-half of 33 ps, and with four mitered corners, the mismatch
for each corner is therefore about 4.125 ps, which agrees well with the model. On the right
side are the measured TDR results for the structure with the jog-outs where the P/N skew
has been decreased substantially.
254
shows that phase mismatch is reduced to 0.75° with jog-outs and 0.3° with
-75
Inner trace with both jog-out and cut-outs
-76
-77
4.95

Figure 11-16: Simulated Phase Response of 45 Degree Bends with Jog-Outs

shows test cases without (left side) and with (right side) jog-outs. There are
Figure 11-17: 90° Mitered Turns without and with Jog-Outs
Figure 11-18 are the results of a differential TDR measurement showing the
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Inner trace with jog-out
Outer signal
Frequency, GHz
Virtex-4 RocketIO MGT User Guide
UG076 (v4.1) November 2, 2008
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