The fastest serial data standards under active development these days are very fast—10-Gbit/s Ethernet and Fibre Channel 8.5. Serial data measurements and jitter analysis on these signals with a real-time scope would require an extremely fast instrument, like LeCroy’s SDA 18000. This serial data analyzer oscilloscope delivers an 18-GHz bandwidth and 60-Gsample/s signal acquisition, with a memory capacity up to 150 Mpoints.
By capturing data in real time rather than on a sampling scope, designers can recover the embedded clock and phase lock to it for precise jitter measurement. A complete breakdown of jitter composition is possible, even with non-repeating or live data. And, the ability to capture long data patterns helps locate the sources of low-frequency jitter modulation or spread-spectrum clocked data.
A completely new feature in the SDA 18000 is Q-scale analysis and plot view, which offers more insight into jitter than traditional measurements. Q-scale analysis uses a different method of breaking down jitter that identifies subcomponents more accurately, instead of classifying them as random jitter. It also improves the way jitter histogram tails are extropolated, improving accuracy, stability, and convergence time. Meanwhile, the Q-scale plot supplies a more intuitive presentation of the nature of the jitter components than does the traditional “bathtub” curve.
LeCroy’s DA18000AC 18-GHz differential amplifier permits high-fidelity acquisition of differential signals while eliminating the need to use long cables for two of the scope’s four inputs. So, designers don’t have to deskew the differences in the electrical length of the cables or precisely adjust the gain balance of the two channels.
The SDA 18000 costs $128,000 with a maximum 24 Mpoints in one-channel operation. The DA18000AC differential amplifier costs $14,495. A 9-GHz, 40-Gsample/s model of the scope costs $90,000. A 50-Mpoint memory option is $4990, and the 150-Mpoint option is $14,990. Delivery is in six weeks after receipt of an order.