Crosstalk Analysis for Symmetric and Asymmetric High-Speed Signal Lines of GDDR6 Package

GDDR6 SDRAM interfaces support high bandwidth (12–16 Gbps) requirements for applications like data centers and networking, offering the fastest SDRAM speeds at low costs and power levels comparable to LPDDR5. Crosstalk at such high speeds significantly impacts the signal margin, necessitating thorough investigation. This study performs a comprehensive crosstalk analysis for 16 Gbps data rates using symmetrical (two coupled traces) and asymmetrical (three coupled traces) signal traces in a package, utilizing the Ansys SIwave tool based on the 2D Method of Moments solver. FEXT (Far-end crosstalk) and NEXT (Near-end crosstalk) coefficients were computed in both frequency and time domains. The analysis revealed that tightly coupled asymmetric traces exhibit higher FEXT values on outer traces compared to the center trace, as the coupled fields on the center trace are terminated on the outer trace, treated as ground. Low impedance victim traces also experience lower induced crosstalk from high impedance aggressors. Symmetric traces, however, show negligible FEXT due to the cancellation of inductive and capacitive coupling. Time domain analysis confirmed that outer traces are aggressors, inducing a peak voltage of 0.2 mV on the center trace, with no significant voltage between outer traces. This work uses a quick application crosstalk scanner instead of full channel S-parameter extraction, saves resources and simulation time, providing early insights into crosstalk behavior crucial for next-generation system designs.