The deterministic jitter
is much higher than random jitter, and the deterministic jitter
is dominated by duty cycle distortion.
For example, if the bit rate is 2.5 Gbps, any line longer than 50/2.5 = 20 inches may have problems with ISI, collapse of the eye diagram and deterministic jitter
. It doesn't mean the interconnect won't work, it just means that if you don't run a simulation you may be surprised by product that doesn't work.
Certain test equipment such as Agilent Infiniium DSO81204A (12 GHz 40 GSa/s) allow jitter measurements on ultra-fast serial signals and can display total jitter, random jitter, deterministic jitter
, data-dependent jitter, as well as pattern and periodic jitter.
This frequency dependence is what causes the rise time degradation, so an attenuation value from dielectric loss is a reasonable first order measure of the ISI, collapse of the eye and deterministic jitter
The units feature real-time waveform displays and a special jitter measurement mode that measures total jitter as well as random and deterministic jitter
Along with the right eye diagram and mask, compliance measurements of eye height, total jitter (Tj), deterministic jitter
(Dj), and random jitter (Rj) are displayed.
When you consider all the different effects lumped under the term signal integrity, it seems like there is a neverending list of problems to keep track of: ground bounce, ringing, crosstalk, switching noise, rail collapse, delta I noise, capacitive coupling, reflections, discontinuities, impedance miss matches, lossy lines, terminations, branches, deterministic jitter
, stubs, decoupling capacitors, loop inductance, via inductance, controlled impedance, time delay, skin depth, return current, layer transitions, differential impedance, collapse of the eye, common signal termination, differential signal termination, overshoot, intersymbol interference, ring back, etc.
This software separates random and deterministic jitter
to help identify the sources of jitter in high-speed digital systems.
Although both types of instrument report TJ, random jitter (Rj), and deterministic jitter
(Dj), they are measuring different quantities." He explained, "We now include the facility to choose either TIA-like edge-to-edge jitter or reference-to-edge jitter using recovered clock edges.
This effect is called intersymbol interference (ISI) and gives rise to the collapse of the eye diagram and deterministic jitter
can be further quantified as ISI (intersymbol interference), DCD (duty cycle distortion) or PJ (periodic jitter).
The measurement of the eye diagram captures the deterministic jitter
in interconnects caused by interconnect crosstalk, losses, and reflections.