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You need to test, we're here to help.

26 July 2017

The Periodic Table of Oscilloscope Tools: Analyze (Part III)

We're nearing the end of our tour of the Periodic Table of Oscilloscope Tools, our way of presenting our broad palette of oscilloscope tools in a concise, clear fashion. In this installment, we'll finish up the Analyze grouping, by far the largest on the Periodic Table.

Analysis of serial data is an important aspect of many design efforts in our information-centric age. Thus, Teledyne LeCroy oscilloscopes provide a useful suite of tools for that purpose.
  • Multi-Lane: Increasing serial data speeds have spawned the use of multiple serial data "lanes," typically from four to 16. These lanes may electrically interfere with each other. Therefore, it is highly desired to analyze multiple serial data lanes simultaneously. Teledyne LeCroy's SDAIII Serial Data Analysis toolset permits up to four active lanes and one reference lane to be analyzed simultaneously using the full toolsets, such as Eye Diagrams; Tj, Rj, Dj jitter decomposition; vertical noise analysis; crosstalk analysis; and various analytical jitter views, such as Bathtub Curve, IsoBER, Rj + BUj Views, DDj + ISI Views, and Pj Spectral Views. 
  • Random Jitter (Rj) plus Bounded Uncorrelated Jitter (BUj) is equal to the total jitter (Tj) "stripped" of all of the data-dependent jitter (DDj). Our analysis tools allow you to calculate Tj, Rj, and Dj, and then view the Rj+BUj with a variety of views to understand the non-data-dependent nature of the jitter. Specialized Jitter Histogram views are provided to understand the distribution of Rj+BUj values, such as a specialized Q-Fit Rj+BUj Histogram view in which Gaussian tails result in straight lines whose slope is equal to 1/Rj. Jitter Track views help understand how the Rj+BUj values change over time and ease correlating the changing behaviors to other acquired and time-correlated signals. Jitter Spectrum views aid in ferreting out root causes of jitter. The Jitter Spectrum view identifies spectral peaks, and displays the peak threshold to aid in understanding. Teledyne LeCroy is the only company to provide all of these Rj+BUj analysis views.
  • DDj + ISI Views: De-convoluting data-dependent pattern jitter (DDj) from deterministic jitter (Dj) is critical to understanding of jitter caused by specific digital pattern sequences, and to correlating them to other system activity. The tool performs automatic digital pattern recognition up to PRBS-23 with only a minimum of 10 patterns required for DDj analysis calculations and views. Users can also define the specific pattern. Then, we calculate total DDj and the components of DDj (duty-cycle distortion, or DCD, and intersymbol interference, or ISI) and display them as measurements. A variety of DDj views can be displayed, such as a data-dependent jitter histogram, DDj plot (or data-dependent jitter track, which plots the DDj time-correlated to the extracted digital pattern, and a plot of the found digital pattern sequence. An ISI plot can also be displayed with user definition of the number of bits included in the ISI plot, and color-coding to specific bit transitions.
  • Periodic Jitter Spectral Views: Periodic jitter (Pj) is the main component of bounded uncorrelated jitter (BUj) and is the primary remaining deterministic jitter (Dj) component of interest once data-dependent jitter (DDj) (see DDj + ISI Views, above) is "stripped" from the total jitter (Tj). To minimize sources of Dj that can lead to a high Tj, Pj must be isolated and understood, and this is accomplished through analysis of the spectral components of the Pj. With knowledge of the spectral components of the Pj, they can be correlated to other in-circuit behaviors and eliminated. Teledyne LeCroy is the only company to provide an ability to isolate and analyze the Pj spectrum using an Inverse FFT of a Jitter Track of the Rj + BUj calculated waveform (which has already "stripped" out the data dependent jitter (DDj) components). This inverse FFT also eliminates the baseline components of the spectrum (the threshold level for this elimination may be viewed overlaid on the inverse FFT). The result—the Pj Inverse FFT—shows only the spectral composition of the periodic jitter so that its root cause can be more easily identified and eliminated.
  • Noise Analysis is the "vertical" equivalent of jitter ("horizontal/time") analysis and consists of vertical noise, random noise (Rn), and deterministic noise (Dn) measurements and an extrapolated total noise (Tn) calculation. The tool provides a breakdown of Dn into intersymbol interference noise (ISIn) and periodic noise (Pn). It provides a variety of analysis functions and views, such as noise-based eye height and width parameters, random noise (Rn) + bounded uncorrelated noise (BUn), noise histogram, Q-fit for noise histogram, Rn+Bun noise spectrum and peak threshold, Pn inverse FFT plot, and Rn+Bun noise track. The noise analysis capabilities, in general, are vertical equivalents of the horizontal (jitter) calculations described for Rj + BUj Views, DDj + ISI Views, and Pj Spectral Views.
  • Crosstalk can be measured numerically through vertical noise analysis and displayed visually as a crosstalk eye-diagram contour plot. The plot is akin to the IsoBER, but includes a plot of the probabilistic extent of noise, both inside and outside the eye. Use Multi-Lane LaneScape Comparison mode to generate crosstalk eyes on multiple lanes, and use the reference lane when performing multi-scenario testing, such as aggressor on/off analysis. Compare two crosstalk eyes from different signals to easily see the result of the analysis. Crosstalk eyes can be overlaid for simple comparisons.
Among the most important aspects of the Periodic Table is our collection of Application Packages. The packages focus the oscilloscope on specific tasks with laser-like precision:
  • EMC and ESD pulse measurements require specialized measurement algorithms to meet the IEC requirements—standard IEEE-defined rise and fall time, width, and other parameters will not meet the requirement. Teledyne LeCroy provides enhanced capability for rise/fall time and width parameters to set the measurement algorithms for base-top (absolute or percent), peak-peak (percent), 0V-maximum (percent) or 0V-minimum (percent). Additionally, specialized measurement parameters for EMC level-at-pulse and EMC time-to-half-life are included. Measurement filters may be used to limit the number of pulses reported in the measurement parameter, or gate the measurement to individual pulses in the acquisition. 
  • Motor + Power: A full-range of toolsets is provided for measuring single-phase to three-phase AC line input to pulse-width modulated (PWM) power supply, inverter, and drive outputs. Measure electrical power quantities, such as real (P), apparent (S), and reactive (Q) power and power factor/phase angle, along with per-cycle RMS voltages and currents. You can measure both Static+Dynamic power quantities over long periods, and also apply Zoom+Gate to limit the measurements to the specific area of interest. Measure harmonic values by order and compare them to a standard. Measure power semiconductor device losses during switching and conduction events as well as on resistance for Si, SiC, and GaN devices. Calculate mechanical (motor shaft) power, or measure it through the use of torque sensors and a wide variety of speed sensors. You can also analyze switch-mode power supply control loops.
  • DDR Analysis comprises a comprehensive set of tools for measurement and analysis of DDR clock and timing behaviors for nearly all varieties of DDR and LPDDR, ranging from QualiPHY compliance validation of DDR standards to various toolsets used for DDR debug. The latter includes: R/W Separation; Multi-Eye View; DDR Tj, Rj, Dj calculation and decomposition; Virtual Probe; and the complete DDR Debug Toolkit to intuitively understand and debug DDR behaviors.
  • Optical: Leading-edge optical communications research and development has long been a driving force in the development of high-bandwidth oscilloscope technology. Our high-bandwidth oscilloscopes using Digital Bandwidth Interleave (DBI) and ChannelSync 4 to 80 Channel architecture have proven instrumental in completing leading edge research in DP-QPSK, DP-16QAM, Coherent MIMO, and Space-division Multiplexed optical transmissions. Our coherent receiver, OpticaLinQ, and PAM-4 Analysis software complete our solution set. 
  • QualiPHY is highly automated compliance test software meant to help you develop and validate the PHY (physical-electrical) layer of a device, in accordance with the official documents published by the applicable standards organizations and special interest groups (SIGs). You can additionally set custom variables and limits to test compliance to internal standards. QualiPHY supports a wide variety of Ethernet; automotive; video; MIPI; PCIe; USB; and storage, serial data, and DDR memory standards to make compliance testing fast and easy.
The next and final installment in our review of the Periodic Table of Oscilloscope Tools will show you the ways in which your Teledyne LeCroy oscilloscope can help you document your work.

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