Application Notes

Signal Integrity Modeling of Gigabit-speed Cables and Connectors Using the TDR

Meritec has long used the TDR (Time Domain Reflectometry) to directly measure impedance and velocity of propagation. We have extended the usefulness of the TDR by adding TDA System's IConnect software to model our connectors and cable assemblies. IConnect uses TDR and TDT (Time Domain Transmission) measurements to extract lumped and coupled RLC models of connectors and lossy line transmission models of cable assemblies. An excellent feature of the software is the capability to predict eye pattern diagrams at high data rates based on TDR/TDT measurements.

The TDA Systems application note discusses their methodology for modeling cables and connectors. Example 1 features our sister company's ( Joy Signal Technology ) Z-Trace coaxial connector and cable assembly.

The following are examples of the capabilities of the IConnect software:

Measure, model, simulate, verify

Create lossy transmission line models

Predicted eye diagram based on TDR/TDT measurements

Extract S-parameters from TDR/TDT measurements

Cascaded model of PC board structure and Z-Trace cable assembly

This application note also appeared as an article
published in EDN Magazine, June 2002.  Click here to view.