SDI Eye and Jitter Measurements
How-to Guide
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Using Infinite Persistence and cursors within the eye or jitter displays allows the user to see the maximum
variations of the SDI signal within the display. In some cases it may be observed that the jitter within the
jitter display or using the jitter meter is lower than that observed within the eye display trace. This is due
to the fact that the jitter display is bandwidth limited to the phase lock loop of the clock within the
instrument in order to represent the typical performance of a video device and to ensure a stable lock to
the SDI signal.
The eye display itself is not bandwidth limited and therefore may show more jitter or wander present
within the SDI signal as shown in Figure 15. In this case very low frequency jitter or wander that is
causing the trace to move within the display, produces large amounts of jitter within the eye. This is not
present within the Jitter display as the bandpass filter limits the frequency band of the resultant jitter. The
jitter meter shows 0.18ns of jitter whereas the measurement of total jitter in the eye display measures
0.217ns.
Figure 15.
Using cursors within Infinite Persistence within Eye Display menu.
