Summary of Contents for Wavecrest SIA-3000
- Page 1 WAVECREST Corporation Examining Clock Signals And Measuring Jitter WAVECREST SIA-3000™ with the Application Note No. 142 200142-00 REV A...
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- Page 3 WAVECREST Corporation continually engages in research related to product improvement. New material, production methods, and design refinements are introduced into existing products without notice as a routine expression of that philosophy. For this reason, any current product may differ in some respect from its published...
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Page 5: Table Of Contents
Contents Introduction ....................1 Amplitude Measurements ................2 Measuring Jitter with Histogram Tool............3 Use Tail-Fit to Separate RJ and DJ ............4 Find the Causes of DJ; Identify PJ, Crosstalk and Modulation ....5 Identify the Spectral Content of the Jitter ........... 6 Identify Possible Low Frequency Jitter Content ......... - Page 6 This page intentionally left blank.
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Page 7: Introduction
XAMINING LOCK IGNALS AND EASURING ITTER WAVECREST SIA-3000™ WITH THE Application note #142 Introduction The purpose of this application note is to highlight the various clock measurement tools available in the software. The basic steps for specific tool setup and VISI interpretation of the resulting plots are covered. -
Page 8: Amplitude Measurements
• Press the SINGLE/STOP button to acquire the signal. The signal will be displayed. For more information on this tool, refer Oscilloscope Quick Reference Guide Figure 1 - Oscilloscope example available at www.wavecrest.com Clock Tools Overview Page 2 of 13... -
Page 9: Measuring Jitter With Histogram Tool
DJ, it is helpful to perform a more comprehensive analysis. When the histogram is Gaussian, the 1-sigma equals the Random Jitter (RJ). The addition of Deterministic Jitter (DJ) will increase the 1-sigma. WAVECREST’s Tail-Fit algorithm can be enabled to better estimate the true RJ. -
Page 10: Use Tail-Fit To Separate Rj And Dj
(right-tail RJ) are displayed below the TJ. Chi-squared values are also displayed as an indication of the goodness of fit from model to acquired measurements. Once DJ has been found, we can determine the causes. available at www.wavecrest.com Clock Tools Overview Page 4 of 13... -
Page 11: Find The Causes Of Dj; Identify Pj, Crosstalk And Modulation
When modulation is present, these 1-sigma values change periodically, as in Figure 4. The example shows alternating high and low values every other edge. Other periodicities are apparent. From these measurements we can determine the periodic jitter frequencies and magnitudes. available at www.wavecrest.com Clock Tools Overview Page 5 of 13... -
Page 12: Identify The Spectral Content Of The Jitter
FFT N-clk view To provide frequency and amplitude of jitter, we use Accumulated Time Analysis, a WAVECREST patented algorithm that creates a frequency vs. jitter diagram. • While still in the High Frequency Modulation tool, you can now change views from the 1-sigma view to the FFT N-clk view. -
Page 13: Identify Possible Low Frequency Jitter Content
Low Frequency Continue analysis of Periodic Jitter (PJ); Identify possible Low Modulation Frequency Jitter content FFT 1-clk view Often it is not necessary to identify jitter at very low frequencies (in this tool <100kHz). Low frequency modulation can be analyzed in the High Frequency Modulation tool, but the acquisition time becomes very long for lower “HPF –3dB freq”... -
Page 14: Analyze Long-Term Drift/Wander
Strip Chart Analyze long-term drift/wander or effects of temperature change or Min/mean/max view supply voltage change on mean measurement values • From the main menu, press Clock, then Strip Chart to open the tool. • The default interval between histogram measurements is 0.1seconds. •... - Page 15 Strip Chart Analyze long-term drift/wander or effects of temperature change or 1-sigma/pk-pk supply voltage change on the 1-sigma and Peak-to-peak values of view histograms • While still in the Strip Chart tool, change the view from “Avg/Min/Max” to “1-Sigma/Pk- Pk”. The default interval between histogram measurements is 0.1seconds. •...
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Page 16: Measure Duty Cycle And Frequency
Statistics: Measure Duty Cycle and Frequency Duty Cycle/ • From the main menu, press Clock, then Statistics to open the tool. Frequency count • Press SINGLE/STOP button on the front panel or the top menu or Press the RUN button on the front panel or the top menu To Measure: Figure 10 - Shows statistics from histogram measurements of Period +, Period-, Pulsewidth +, Pulsewidth -, Duty Cycle, and Frequency Counter. -
Page 17: Measure Cycle-To-Cycle
Cycle-to-cycle Measure Cycle to Cycle Accumulated view • From the main menu, press Advanced Clock, then Adjacent Cycle to open the tool. • Press SINGLE/STOP button on the front panel or the top menu or Press the RUN button on the front panel or the top menu To Measure: Figure 11 - Shows statistics from histogram measurements of Cycle-to-Cycle (or the difference of two adjacent cycles), Period, and Duty Cycle. -
Page 18: Measure Skew Or Propagation Delay
Skew Measure Skew or Propagation Delay Propagation • From the main menu, press Chan to Chan then Propagation Delay and Skew to open delay the tool. • Press SINGLE/STOP button on the front panel or the top menu or Press the RUN button on the front panel or the top menu To Measure: Figure 12 - Shows statistics from histogram measurements of Skew or... -
Page 19: Conclusion
Conclusion SIA-3000 provides the ability to measure and graphically display many different critical clock parameters. Using the tools described in this application note, a characterization or test engineer can understand the output of the part under test in just a few minutes. Each tool has additional capabilities not described in this application note. - Page 20 WAVECREST Corporation World Headquarters: West Coast Office: Europe Office: Japan Office: 7626 Golden Triangle Drive 1735 Technology Drive, Ste. 400 Hansastrasse 136 Otsuka Sentcore Building, 6F Eden Prairie, MN 55344 San Jose, CA 95110 D-81373 München 3-46-3 Minami-Otsuka TEL: TEL:...