Table of Contents:

Definition and Overview

1. Introduction

2. Broadside versus Edge-Coupled Differential Pairs

3. Point of Diminishing Returns: Line Width Increases

4. Mechanical Materials Properties

5. Launch Issues

6. System Measurements

7. Conclusion

8. Appendix

Self-Test

Glossary

PDF of this tutorial

Definition
Engineers continually access new technologies when making architectural decisions for their new products. The consumer demand for more system bandwidth is common, as is the need to balance high system speed with the reality of establishing cost/performance/risk tradeoffs for electronic equipment. The designer may have constraints that dictate certain design parameters; others remain open for selection. In the design of a backplane interconnect system, a myriad of options is available for printed circuit (PC) board materials, trace topologies, and connectors. Launches from the connector to the board and trace lengths must also be considered to reach system performance goals as designers optimize the system. Part of this optimization includes achieving the electrical integrity necessary to pass such signals while maintaining mechanical attributes and cost tradeoffs.

Overview
This tutorial explores high-speed backplane-interconnect system tradeoffs related to the effects on increases in bandwidth on the signal path from driver to receiver through printed circuit boards (PCBs).