xrt75r12 Exar Corporation, xrt75r12 Datasheet - Page 40

• Manufacturer Part Number: xrt75r12
• Description: Twelve Channel E3/ds3/sts-1 Line Interface Unit With Jitter
• Manufacturer: Exar Corporation

XRT75R12
TWELVE CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT WITH JITTER ATTENUATOR
There are three fundamental parameters that describe circuit performance relative to jitter
Jitter tolerance is a measure of how well a Clock and Data Recovery unit can successfully recover data in the
presence of various forms of jitter. It is characterized by the amount of jitter required to produce a specified bit
error rate. The tolerance depends on the frequency content of the jitter. Jitter Tolerance is measured as the
jitter amplitude over a jitter spectrum for which the clock and data recovery unit achieves a specified bit error
rate (BER). To measure the jitter tolerance as shown in
modulation of the serial data bit sequence. Input jitter tolerance requirements are specified in terms of
compliance with jitter mask which is represented as a combination of points. Each point corresponds to a
minimum amplitude of sinusoidal jitter at a given jitter frequency.
Bellcore GR-499 CORE specifies the minimum requirement of jitter tolerance for Category I and Category II.
The jitter tolerance requirement for Category II is the most stringent.
as per GR-499 specification.
F
5.0 JITTER
5.1
5.1.1
IGURE
Jitter Tolerance
Jitter Transfer
Jitter Generation
25. J
J
ITTER
DS3/STS-1 Jitter Tolerance Requirements
ITTER
T
OLERANCE
T
Synthesizer
OLERANCE
Generator
Pattern
FREQ
Modulation
Freq.
M
EASUREMENTS
Data
XRT75R12
DUT
37
Figure
Clock
25, jitter is introduced by the sinusoidal
Figure 26
shows the jitter tolerance curve
Detector
Error
REV. 1.0.4