This month I penned a massive work on the subject of crosstalk in BGA packages, the sort of thing we usually call "ground bounce", or "Vcc bounce". This 20-page white paper compares theory, simulation, and measured reality.
It includes a brief section outlining the nature of BGA crosstalk, highlighting the shortcomings of simplistic ground-bounce models that focus on the concept of ground-pin inductance. It then shows actual measured data from two high-speed FPGA components (Xilinx® Virtex™-4 LX60 and Altera® Stratix® II LS60) pumping maximum current into as many as 500 simultaneous outputs. The correspondence between calculated and measured data is as striking as is the difference in performance between package types.
If you haven't seriously studied BGA packaging and crosstalk, now is the time to learn something about the subject.
I was really jazzed about being able to use the latest Tektronix 8-GHz scope for this project. The resolution with averaging on this instrument is just fantastic and the pictures come through crystal-clear.
The free live web seminar
about this paper is done and gone, the complete paper in .pdf
format appear here:
Thanks to Xilinx, Inc. for their support of this work, and Tektronix, Inc. for supplying the measurement equipment.