Xilinx Virtex-5 RocketIO GTP User Manual page 242

Chapter 13: Design of Transitions
As shown from
yields a significant improvement in the performance of an SMT pad transition. Excess
capacitance is reduced by 15x and return loss is improved by 20 dB.
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Figure 13-9: TDR Results Comparing 0402 Pad Structures
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0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00
Figure 13-10: TDR Results Comparing 0402 Pad Structures
Figure 13-11 and Figure
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Time, ns
Time, ns
13-12, clearing the ground plane under SMT pads
Virtex-5 RocketIO GTP Transceiver User Guide
R
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