STANDARD PRODUCT
PM4351 COMET
DATA SHEET
PMC-1970624
ISSUE 10
COMBINED E1/T1 TRANSCEIVER
1/96 UI phase adjustment quantum. TJAT meets the jitter attenuation
requirements of AT&T TR 62411. The block allows the implied jitter attenuation
requirements for a TE or NT1 given in ANSI Standard T1.408, and the implied
jitter attenuation requirements for a type II customer interface given in ANSI
T1.403 to be met.
Jitter Tolerance
Jitter tolerance is the maximum input phase jitter at a given jitter frequency that a
device can accept without exceeding its linear operating range, or corrupting
data. For TJAT, the input jitter tolerance is 61 Unit Intervals peak-to-peak (UIpp)
with a worst case frequency offset of 354 Hz. It is 80 UIpp with no frequency
offset. The frequency offset is the difference between the frequency of XCLK
and that of the input data clock. Values above 2 kHz in the below graph are
based on simulation results.
Figure 9
100
- TJAT Jitter Tolerance
61
JAT
MIN.TOLER
ANCE
28
10
JITTER
AMPLITUDE,
UI pp
1.0
0.1
acceptable
0.4
unacceptable
0.01
10
1
100
JITTER FREQUENCY, Hz
1k
10k
100k
The accuracy of the XCLK frequency and that of the TJAT PLL reference input
clock used to generate the jitter-free TCLKO output have an effect on the
minimum jitter tolerance. Given that the TJAT PLL reference clock accuracy can
PROPRIETARY AND CONFIDENTIAL
59
PMC [ PMC-SIERRA, INC ]
