Electronic Design

Sampling Scope Optimized For Fast Serial Data T&M

With so many recent designs using one of the super-fast serial data buses, it's not surprising that someone would introduce a test instrument optimized for making measurements in these systems. LeCroy's WaveExpert 100H sampling oscilloscope can acquire, measure, and process signals that cannot be physically probed.

This modular scope addresses the analysis and interoperability compliance of the long serial data patterns required by PCI Express, Serial ATA, XAUI, 10-Gigabit Ethernet, and other standards. It also supports up to four optical or electrical input channels with bandwidths up to 100 GHz as well as clock recovery and serial pattern generation up to 13.5 Gbits/s.

Optimized for jitter analysis and eye diagram measurements, it includes time domain reflectometry (TDR) software with s-parameter measurements for differential two-port circuits or buses. This lets users characterize cables, connectors, backplanes, and other devices. Scope measurements like pulse rise, fall, amplitude, and period are standard.

The WaveExpert 100H also includes Eye Doctor, a virtual probing and measurement system. LeCroy recently introduced the Eye Doctor software as an accessory for its WaveRunner oscilloscopes. Standard on the 100H, Eye Doctor is useful in situations where physical probing disturbs the signal to the extent that no accurate measurement can be made.

In most serial data systems, a transmitter is connected to a transmission line, backplane, cable, or other medium that takes the signal to a receiver. Probing at the transmitter is acceptable because of the strong signal at that point. But probing at the receiver input where the signal is weak, noise is high, and distortion is great is not practical because of the loading effects of even the best high-frequency probes.

Eye Doctor can be used here because it simulates signals at a desired point in a network using measurement from a different point. It takes the measurements at the transmitter output and, using the TDR s-parameter software output representing the channel, it simulates what the receiver input will look like. The output is the eye diagram expected at the receiver. Users also can bring into play built-in equalization such as feed-forward equalization (FFE) or decision-feedback equalization (DFE) to see what the ideal receiver output response will be.

The 100H significantly improves jitter analysis compared to other instruments. Because of the new high-stability coherent interleaved sampling (HCIS) time base, its high sampling rates, and huge data storage, the 100H can capture more data faster. This means jitter measurements that are better than the spectrum-based methods commonly used now. The scope's innovative Q-scale jitter analysis capability provides more accurate jitter measurement regardless of type or source of jitter. The jitter noise floor is 230 fs.

The very high sampling rates also deliver unprecedented depth to eye-pattern analysis, rivaling only bit-error-rate test sets in its ability to detect and measure low-probability events. A conventional sampling scope can capture only about 40 ksamples/s while the 100H can capture 2.5 Msamples—that’s 60 times faster.

While the basic storage capacity is 4 Msamples per channel, users can expand to 128 Msamples per channel and 510 Msamples on a single channel. Sampling heads with rates of 20, 30, 50, 70, and 100 Gsamples/s are available. Sampling heads for optical inputs are available in 10-, 28-, and 50-Gsample/s versions. The jitter analysis and Eye Doctor features are also options.

The base price of the chassis with TDR and s-parameter software is $21,250. For more details and option prices, contact LeCroy.

LeCroy Corp.


TAGS: LeCroy
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