User guide

The jitter amplitude is usually specified in UI. One UI (Unit Interval) is always the
reciprocal of the present data rate. For example, if the data rate is set to 2 Gbit/s,
one UI corresponds to 500ps.
This kind of jitter can be picked up from any adjacent signal or clock. The jitter
histogram has a U-shape.
Triangular jitter is always generated by a spread spectrum clock but can also be
caused by other periodic sources. Triangular jitter has a uniform jitter distribution.
Intersymbol Interference
Intersymbol interference (ISI) is caused by bandwidth limitations of cables and
backplanes. It cuts off higher frequencies and hence changes the shape of the eye
opening.
Jitter Tolerance Tests 8
Agilent J-BERT N4903B High-Performance Serial BERT 399
Sinusoidal Jitter
Triangular Jitter