AN 684: 100 Gbps CFP2 Design with Stratix V GT FPGAs

ID 683219
Date 1/16/2014

1.4. BGA Breakout Optimization

BGA breakout optimization targets both the BGA pads and dog bone vias. A cutout is provided in the reference plane under the BGA pad and large oval via anti-pads are used for better BGA pad and via impedance matching.

Figure 8.  BGA Via Breakout Layout Optimization

Figure 9.  TDR of BGA Via Breakout HFSS simulation results show that the TDR deviation of the BGA escape is maintained within ±10% of the nominal 100Ω channel target impedance.