Signal Integrity Testing for High Speed Serial Data
Objectives The material will cover techniques for TDR probing and testing a wide variety of high speed serial data devices.The majority of the material focuses on practical examples for capturing, viewing and measuring signals more accurately in the time and frequency domain and for characterizing imperfections in a signal path.The overall objective is to train engineers to use the best practices in probe, socket and scope usage for the most precise signal integrity measurements in order for them to get the best possible product to market as soon as possible. Target Audience Engineers who design/test prototype parts and evaluation boards for high speed clocks or serial data streams, who design semiconductor devices, serial data components or circuits where signal shape is important will benefit from this seminar.Focus is on methods to most accurately probe, capture, view, measure and analyze real time or repetitive signals. Design or Engineers who need to select sockets, probes and characterize the shapes of multigigahertz signals and who desire practical advice for troubleshooting the sources of signal integrity problems.
A Technical Discussion of TDR Techniques, S-parameters, RF Sockets, and Probing Technologies for: High Speed Serial Data Designs
Content: * Why do we need TDR? * What is TDR? * TDR Block Diagram * What is TDT? * Differential TDR/TDT * Basic TDR Measurements * Sources of Inductance and Capacitive discontinuities (socket, connectors, etc.) * Solutions for eliminating interconnect LC discontinuities, improving return loss * Using TDR to locate discontinuities and open/short faults * Enhancing TDR measurements through calibration (normalization) * TDR rise time considerations (how fast of a TDR do I need?)
Many TDR instruments can produce S-parameters extracted from the time domain TDR waveforms so it is important to understand S-parameters
* What are S-parameters? * Impedance measurements in the Time and Frequency domain * Comparison of TDR derived S-parameters vs. VNA (are they as accurate?) * TDR probe selection
Characterizing Device Evaluation Test board – Measure Differential Board Impedance – Measure impact of pogo pin socket on: • Impedance, Time Skew, Eye Diagram – Measure Differential S11/21 from • RF Pogo pin socket to SMA • Comparing long and short traces • Example of lossy traces
Test Socket Interposers Discontinuity Impact on 6Gbit Eye Diagram Comparing Pogo pin vs. Diamond Interposer vs. Soldered Test sockets on a 6Gbit Eye Diagram Useful Links