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Digital Storage Scopes Leverage SiGe, Windows 2000, Packetized Data Flows

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LeCroy Launches Powerful Line of Mid-Range Oscilloscopes WavePro 7000 Series Sets Price/Performance Standard for 1 GHz to 3 GHz Oscilloscopes Chestnut Ridge, New York--LeCroy Corporation, a leading supplier of high-performance digital oscilloscopes, announced that it has launched a new series of 1 GHz and 3 GHz digital oscilloscopes. The WavePro 7000 Series provides higher performance in terms of Sample Rate, Memory Length, and Processing Power than any competitive products at attractive prices. "Following the successful launch one year ago of the WaveMaster—still the world's highest performing digital oscilloscopes—we began work to leverage key high-end technologies down through our entire product line," said LeCroy President and CEO Tom Reslewic. "The WaveMaster's award-winning MAUI (Most Advanced User Interface) and high-performance silicon germanium (SiGe) acquisition system have received great acclaim from customers and the trade press. Now, these industry-leading technologies are available on all LeCroy scopes in the $18,000 to $90,000 price range. "We expect the WavePro 7000 series to appeal to a broad range of customers in the sweet spot of the oscilloscope market—just below the high end," continued Reslewic. "These products are designed to be highly flexible and versatile, accommodating a wide range of electronic signals and customer applications. Customers in a variety of industries will be able to take advantage of LeCroy's superior WaveShape Analysis features found in the WavePro 7000 family." The new WavePro 7100 and WavePro 7300 digital oscilloscopes incorporate LeCroy's patented MAUI Software Technology, SiGe amplifiers, and SiGe A/D converters, which previously were available only with the Company's high-end WaveMaster instruments. Like the WaveMaster products, the WavePro Oscilloscopes utilize a proprietary, extremely fast processing architecture for handling and analyzing complex measurements. WavePro also allows the user to insert customized, proprietary, or even classified measurement algorithms directly into the scope's processing path rather than through a separate application like other manufacturers. This unique approach allows engineers to make more precise measurements at speeds 10 to 100× faster than with any other alternative. In addition, the new WavePro models offer a "best-in-class" maximum sample rate of 10 GSamples/s on each of four channels. LeCroy is the first company to offer this performance on oscilloscopes with 1 GHz and 3 GHz bandwidths. WavePro oscilloscopes are priced in the U.S. from $18,500 to $39,000.

Since our review and analysis in ChipCenter about three years ago when the WavePro line debuted, LeCroy has been augmenting its Windows-equipped product line-up. With this news, LeCroy alters and expands its WavePro family, proving that the company is in lockstep with rapidly evolving application requirements and the users of digital storage scopes. At the same time, these latest instruments pack features that will likely appeal to analog scope diehards, too. More on that in a moment. From a historical perspective, these two 800 × 600 pixel color-touchscreen models update the bandwidth, sampling rate, memory, and analysis functions of the company's previously introduced scopes, namely the 500 MHz WavePro 940 (now discontinued), the 1 GHz WavePro 950, and the 2 GHz WavePro 960. Equipped with 1.7 GHz (or faster) Intel processors, and up to 1 Gbyte of RAM, these new boxes run Windows 2000. That lends them to PC-oriented user interaction—and lots of it. The 1 GHz Model 7100 and the 3 GHz WavePro 7300 are also designed to meet market-competitive price vs. performance points. That's something that may complicate or ease your product selection process. In any case, you stand to benefit from deep memory and 10:1 oversampling. If you're involved with high-speed datacom or telecom, or technologies such as Gigabit Ethernet or high-speed Universal Serial Bus, these oscilloscopes can open a window to the kind of signal analysis that's commensurate with those technologies. They're very state-of-the-art. For starters, both the 7100 and 7300 pack circuitry to ensure accurate signal capture. The sampling rate of both four-channel instruments is 10 Gsamples/s/channel, with a maximum sample rate of 20 Gsamples when they're operated in a two-channel mode. This permits up to 24 million points to be acquired in the four-channel mode, and a whopping 48 million points in dual-channel. Both WavePro scopes offer a choice of acquisition memory lengths starting with a standard implementation of 1 Mpoint/channel on each of the four input channels, and extending to 24 Mpoints/channel. Intermediate memory choices are 2 Mpoints/channel, 8 Mpoints, and 16 Mpoints. In all cases, the memory length is doubled if only one or two of inputs are used. For its part, the 7300 is also claimed to be the first scope to offer 3 GHz performance on low-Z (50 W) lines (with a 5 V maximum input restriction). However, these models also include high-Z inputs accommodating up to 100 V signals, perfect for capturing signals out to 500 MHz. Input-impedance choices are touchscreen-selectable. Streaming Data Given the extraordinary sampling rates of such instruments, you can see that data records could easily become excessive. For example, a 20 point/ns sampling rate can produce a million points of data when capturing a 50 µs signal. To deal with this problem, LeCroy uses its patented X-Stream approach. In X-Stream, data records are packetized and streamed to the system's embedded microprocessor. According to LeCroy, the technique guarantees fast analysis and optimizes cache memory. In operation you can zoom into a signal, and not only pinpoint a glitch or error, but also use waveshape tools to find the cause. You can also create your own parameter measurement and/or waveform math functions, and then insert your algorithm into the processing stream of these oscilloscopes. You need not export data out of the oscilloscope to do this. Speaking of math functions, LeCroy's math tools let you crunch a waveform displayed on any channel, or a waveform that's recalled from any of four reference memories. You can also do computations in sequence. For example, you could set up Trace A as the difference between Channels 1 and 2, with Trace B as the average of A, and Trace C as the integral of B. You could then display the integral of the averaged difference between Channels 1 and 2. click for full-size image Any trace and function can be chained to another trace and function, too. For example, you could make Trace A an average of Channel 1, Trace B a fast Fourier transform (FFT) of A, and Trace C a zoom of B. Analog Persistence Complementing the math functions, LeCroy's new scopes also have what the company calls analog persistence. It's needed because data manipulation and the comparison of acquisitions and statistical analysis are difficult in analog scopes. Nonetheless, analog scopes have their advantages. Because they don't use A/D conversion, the speed of an analog scope is limited only by the bandwidth of its electronics, and signals are monitored continuously. However, a digital scope captures signals across a time period dictated by the size of its acquisition memory. Then the data are processed and displayed, incurring more latencies. In contrast, LeCroy's analog-persistence mode decouples data accumulation from display functions, permitting the fast accumulation and display of new data. That's because the display is generated by repeated sampling of the amplitudes of events over time, and the accumulation of the sampled data into 3-D display maps is used to create an analog-style display. User-definable persistence duration can be used to view how the maps evolve proportionally over time. The persistence is also variable. If you select Analog from the system's persistence menu, each channel and its associated persistence data map are assigned a color. As a map develops, different shades of this color are assigned for minimums and maximums. The Analog Persistence view highlights the distribution of data so that you can examine it in detail. Another nifty feature is what LeCroy calls Color-Graded persistence. It's similar to Analog Persistence, but uses multiple colors to map signal intensity. When you select Color Graded from the Persistence menu, the WavePro uses a spectrum of color instead of the brightness of a single color to display persistence. Let's return to the WavePro's conditioning and processing hardware, because there's something else noteworthy here. At the front end of LeCroy's X-Stream architecture is silicon-germanium (SiGe) technology. SiGe is used in the input amplifiers, in the system's high-speed A/D converters, and in its fast trigger circuits. SiGe-based blocks track applied signals, digitizing them at 10 Gsamples/s. Then the data are streamed to CMOS memory. It, in turn, can accept the 10 Gbyte/s data rate for up to 24 million points of acquisition. Finally, X-Stream data are transferred over a data bus to the system's CPU and Level 1 (L1) cache. Cache Processing Instead of handling the long data array produced by a high sampling-rate A/D converter as a single multi-Mbyte data array, X-Stream hardware packetizes it. While the L1 cache on a microprocessor can't handle a multi-Mbyte data dump, X-Stream code lets the packets (and the analysis routines for performing measurements on the packets) to be simultaneously resident in cache. The result is a fast extraction of useful information from long arrays. This process eliminates the fetching of data and math instructions from RAM. An interesting facet of this technique is the fact that you can also insert your own instructions into an X-Stream flow, using LeCroy's XDEV option. A VisualBASIC script, or a MatLab or Mathcad file, or even an Excel spreadsheet calculation, can be added to the list of signal-parameter calculations or the system's Waveform Math functions. You could, for example, apply a custom filter created in MatLab, and then look at a persistence display, or apply an FFT. To do this, you won't have to run any other programs, nor establish remote communications between one of these scopes and other programs. You won't have to create a new reference waveform, or transfer any data files. Once defined, the implementation of a custom measurement or a customized function is enabled by a straightforward cut-and-paste operation under Windows. Got The Jitters? A software option not mentioned in LeCroy's press release, but significant for high-speed serial data stream analysis, is a jitter analysis package. The company's JTA-2 option aids measurement of a variety of timing parms, including period, width, and cycle-to-cycle characteristics—all necessary to ensure good signal serial integrity. You also get a variety of ways to analyze your jitter measurements. The results can be presented as statistics, histograms, or time-domain tracks. You can also do a jitter FFT to get a frequency-domain spectral view of a signal's jitter source, looking for things such as harmonic content. LeCroy also offers a version of the popular Amherst Associates jitter program. It's worthwhile noting that this option relies on the scope's inherently ultra-stable hardware that ensures 5 ppm clocking stability and a 1 ps jitter noise floor. Other software package options include serial data mask testing, disk drive measurement, advanced math, Web editing, IIR, and FIR filtering packages. Thanks to Windows, LeCroy also offers an optional high-resolution graphics printer that can pump out hardcopy waveshape images in about ten seconds a page. A removable hard drive option is also available that gives you two removable drives and a USB CD-ROM. Probes to Match LeCroy also offers probes for these scopes, including 1.5 GHz and 3.5 GHz active types, and an O/E (optical-to-electrical) converter. Current probes, with up to 50 MHz of bandwidth, and a capacity to measure up to 500 A, are also available. Differential amplifier probes are options, too. In closing, check out LeCroy's Web site. I think you'll have as much fun navigating it as you could have navigating the oscilloscopes themselves. The Web site gives you an interactive way to check the specs on these new instruments as well as a way to gather and evaluate options.

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