A study of split and common ground referencing schemes for a high speed bus

Two different module referencing schemes, one with split ground planes between transmit/receive (TX/RX), and the other with a common ground plane, are first compared using models generated from 3D full-wave solver, and then the two different module designs are built and tested. The measurements performed and test data on the manufactured modules includes TX output high-low amplitude, eye height, RX jitter tolerance, Phase-Lock-Loop (PLL) interference, and jitter transfer function testing for the transmitter. The data indicates that the common ground referencing scheme results in superior performance for the high speed interface.