Advanced Signal Integrity For High-Speed Digital Designs

4

CROSSTALK

4.1 Mutual Inductance and Capacitance

4.1.1 Mutual Inductance

4.1.2 Mutual Capacitance

4.1.3 Field Solvers

4.2 Coupled Wave Equations

4.2.1 Wave Equation Revisited

4.2.2 Coupled Wave Equations

4.3 Coupled Line Analysis

4.3.1 Impedance and Velocity

4.3.2 Coupled Noise

4.4 Modal Analysis

4.4.1 Modal Decomposition

4.4.2 Modal Impedance and Velocity

4.4.3 Reconstructing the Signal

4.4.4 Modal Analysis

4.4.5 Modal Analysis of Lossy Lines

4.5 Crosstalk Minimization

4.6 Summary

References

Problems

As described in Section 3.2, a signal propagates along an interconnect in the form of an electromagnetic wave established between two (or more) conductors. When neighboring transmission structures are in close proximity, the electric and magnetic fields from the signal will fringe and interact with adjacent conductors. The interaction of fields induces the coupling of energy from one transmission structure to another when a stimulus is applied. This is called crosstalk. Since most digital systems use signaling interfaces in which large numbers of transmission lines are routed in parallel through packages, connectors, and printed circuit boards, crosstalk can play an important role in determining the performance of the system. Trends toward smaller and faster systems will drive increased crosstalk levels in the future, resulting in two major impacts. First, crosstalk will affect signal integrity and timing by modifying the propagation characteristics of the lines (characteristic ...