Eye Opening - Agilent Technologies E5406A-Pro Series User Manual

4
Operating the E5402A, E5405A, and E5406A-Pro Series Probes

Eye Opening

Logic
Analyzer
w/ EyeScan
Driver
Rsource
50 Ω
56
The eye opening at the logic analyzer is the truest measure
of an analyzer's ability to accurately capture data. Seeing the
eye opening at the logic analyzer is possible with Eye Scan.
The eye opening viewed with Eye Scan helps the user know
how much margin the logic analyzer has, where to sample
and at what threshold. Any probe response that exhibits
overshoot, ringing, probe non- flatness, noise, and other
issues all deteriorate the eye opening seen by the logic
analyzer. The following eye diagrams were measured using
E5402A, E5405A, and E5406A- pro series soft touch probes
and Eye Scan while probed mid- bus on a 50Ω transmission
line load terminated at the receiver. The data patterns were
generated using a 2
E5382A
Probe
PRBS
output
Z0=50 Ω
Figure 40
The following plots were made on an Agilent 16760A logic
analyzer using an Agilent 8133A pulse generator with a
250 ps rise time converter. The following measurements use
Eye Scan to show the margin at 800, 1250, and 1500MT/s.
The amplitudes are indicated in the captions.
23
- 1 pseudo random bit sequence (PRBS).
Z0=50 Ω
Eye opening measurement schematic (E5402/05/06A)
E5400-Pro Series Soft Touch User's Guide
Receiver
Rterm
50 Ω