Scopes achieve 80G-sample/sec acquisition, bandwidth to 30 GHz
By Dan Strassberg, Contributing Technical Editor -- EDN, January 6, 2009
LeCroy’s latest introduction, the 8 Zi line, includes WaveMaster digital oscilloscopes, serial-data analyzers, and disk-drive analyzers. The devices provide bandwidth as high as 30 GHz; acquisition of as many as 80G samples/sec; 512 million points of analysis memory, not including the acquisition memory; and edge triggering at more than 15 GHz. The devices also feature waveform analysis as fast as 100 times that of competitive units and a 15.3-in., 16-to-9-aspect-ratio, high-definition touchscreen display with 50% more area than that of 12.4-in. displays. The units tout precise Eye Doctor signal-integrity tools and selectable 50Ω or 1-MΩ input impedance. The units also have TriggerScan rare-event-capture capability, removable front panels, optional integrated second displays, and external data transfer rates as fast as 250 million points/sec—25 to 50 times as fast as other methods.
The 8 Zi line uses one hardware platform that the manufacturer configures as three series, which include 18 models with bandwidths ranging from 4 to 30 GHz. This approach lets you purchase only the bandwidth and features you need yet lets you keep pace with emerging high-speed technologies and serial-data standards by upgrading to greater bandwidth as your requirements change. This capability is attractive in today’s lean economic times because it lets you pay initially for only the bandwidth you need but allows you to upgrade when necessary to 30 GHz of real-time bandwidth without paying for multiple instruments.
On units equipped for 20 to 30 GHz bandwidth, the standard acquisition rate is 80G samples/sec/channel on two channels when you use the full-bandwidth DBI (digital-bandwidth-interleave) mode. The patented DBI technology differs from time interleaving of ADCs and associated acquisition memory, which is common in high-performance real-time scopes. In addition, DBI provides wider bandwidth with lower noise, uncertainty, and waveform artifacts than do techniques that use digital-signal processing alone to extend bandwidth. The DBI-equipped scopes also let you use all four channels at reduced bandwidth. In that mode, the maximum acquisition rate is 40G samples/sec/channel.
Within the WaveMaster 8 Zi series, scopes that lack DBI provide bandwidths of 4 to 16 GHz, with a maximum acquisition rate of 40G samples/sec on all four channels and an acquisition-memory depth of 10 million points/channel or, optionally, as much as 256 million points/channel. These scopes also offer the option of adding the DBI mode with its higher bandwidth and sampling rate. In the DBI mode, the acquisition-memory depth doubles to a maximum of 512 million points on each of the two channels.
For serial-data applications, the eight models in the 8 Zi SDA (serial-data analyzer) series offer the same 4- to 30-GHz bandwidth, sample rate, and analysis-memory as the WaveMaster units but provide standard acquisition memory of 20 million points/channel. To test for compliance with PCIe (peripheral-component-interconnect express) 3.0 and USB (Universal Serial Bus) 3.0 standards, all SDA units also include a 3.125-Gbps serial-trigger capability, which operates on patterns as long 80 bits, and the manufacturer’s SDA II tools.
The SDA II tool set incorporates superior jitter-decomposition techniques and precise jitter-breakdown tools, which increase confidence in measurements and quickly provide detailed insights into device-under-test behavior. The SDA II tools also perform eye-diagram analyses as much as 100 times as fast as do competitive tools—capturing, analyzing, and displaying nearly 1 million unit intervals of PCIe activity in 3 sec. Additional tools, such as IsoBER (bit-error-rate), which identifies constant BER contours on eye diagrams, and mask-violation locator, simplify understanding complex problems. To reduce timing and amplitude errors in high-speed eye diagrams, a cable de-embedding feature removes cable-induced distortion. The SDA 8 Zi units also provide complete, simultaneous views of eye diagrams, time-interval error, bathtub curves, jitter histograms, and other jitter-breakdown analyses. US list prices for 8 Zi scopes range from $59,490 to $209,490. Delivery for units without the DBI feature is eight weeks after receipt of order. For units with DBI, delivery is 26 weeks.
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You need to correct the headline spec in the article from 30MHz to 30GHz.
Tricky - 2009-8-1 00:26:00 PST
