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83056_16 Datasheet, PDF (7/15 Pages) Integrated Device Technology – 6:1, Single-Ended Multiplexer | |||
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83056 Data Sheet
ADDITIVE PHASE JITTER
The spectral purity in a band at a speciï¬c offset from the fundamental
compared to the power of the fundamental is called the dBc Phase
Noise. This value is normally expressed using a Phase noise plot
and is most often the speciï¬ed plot in many applications. Phase
noise is deï¬ned as the ratio of the noise power present in a 1Hz
band at a speciï¬ed offset from the fundamental frequency to the
power value of the fundamental. This ratio is expressed in decibels
(dBm) or a ratio of the power in the 1Hz band to the power in the
fundamental. When the required offset is speciï¬ed, the phase noise
is called a dBc value, which simply means dBm at a speciï¬ed offset
from the fundamental. By investigating jitter in the frequency domain,
we get a better understanding of its effects on the desired application
over the entire time record of the signal. It is mathematically possible
to calculate an expected bit error rate given a phase noise plot.
Additive Phase Jitter @ 155.52MHz
(12kHz to 20MHz) = 0.19ps typical
OFFSET FROM CARRIER FREQUENCY (HZ)
As with most timing speciï¬cations, phase noise measurements have
issues.The primary issue relates to the limitations of the equipment.
Often the noise ï¬oor of the equipment is higher than the noise ï¬oor
of the device. This is illustrated above. The device meets the noise
ï¬oor of what is shown, but can actually be lower. The phase noise
is dependant on the input source and measurement equipment.
©2016 Integrated Device Technology, Inc
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Revision B March 10, 2016
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