XRT91L31 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT91L31' PDF : 41 Pages View PDF
XRT91L31
STS-12/STM-4 OR STS-3/STM-1 SONET/SDH TRANSCEIVER
REV. 1.0.2
The jitter transfer function is a ratio between the jitter output and jitter input for a component, or system often
expressed in dB. A negative dB jitter transfer indicates the element removed jitter. A positive dB jitter transfer
indicates the element added jitter. A zero dB jitter transfer indicates the element had no effect on jitter.
The jitter attenuator within the XRT91L31 meets the latest jitter attenuation specifications and/or jitter transfer
characteristics as shown in the Figure 26 and Figure 27.
FIGURE 26. JITTER TRANSFER FOR OC-12
5
0
-5
-10
-15
-20
-25
100
Jitter Transfer, OC12 (Low Bandwidth)
Mask
Jitter Transfer
1000
10000
100000
1000000
Frequency (Hz)
10000000
FIGURE 27. JITTER TRANSFER FOR OC-3
Jitter Transfer, OC-3 (Low Bandwidth)
Mask
5
Jitter Transfer
0
-5
-10
-15
-20
-25
100
1000
10000
100000
1000000
Frequency (Hz)
10000000
4.6.3 Jitter Generation
Jitter generation is defined as the amount of jitter at the STS-N output in the absence of applied input jitter. The
bandwidth is set according to the data rate. The Bellcore and ITU requirement for this type jitter is 0.01UI rms
measured with a specific band-pass filter.
For more information on these specifications refer to Bellcore TR-NWT-000253 sections 5.6.2-5 and GR-253-
CORE section 5.6 and ITUT G.783 section 9.3.1.1. Table 19 below shows the jitter generation limits per
BellCore GR-253 and ITUT G.783 versus XRT91L31 typical jitter performance.
36
Share Link: 
