High-Speed Interconnect Tuning by Time-Domain Reflectometry

Application ID: 46951

In signal integrity (SI) applications, time-domain reflectometry (TDR) is a useful technique for analyzing the discontinuity in a signal path by observing the reflected signal strength. The reflected signal distorts the input pulse mainly by impedance mismatch if there is no external noise source, crosstalk, or undesired coupling.

In this example, a staircase step function with a fast rise time is launched on a microstrip line connected from layer to layer through a metalized via hole. The signal path discontinuities are identified and the circuit is tuned to lower the distortion based on the TDR impedance calculation.

This model example illustrates applications of this type that would nominally be built using the following products: