XRT73L02M Datasheet, PDF (29/46 Pages) Exar Corporation – TWO CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT

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XRT73L02M
TWO CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. 1.0.0
The Equalizer also contain an additional 20 dB gain stage to provide the line monitoring capability of the resis-
tively attenuated signals which may have 20dB flat loss. This capability can be turned on by setting the
RxMON_n bits in the control register or by setting the RxMON pin “High”.
5.0.1.1 INTERFERENCE TOLERANCE:
For E3 mode, ITU-T G.703 Recommendation specifies that the receiver be able to recover error-free clock and
data in the presence of a sinusoidal interfering tone signal. For DS3 and STS-1 modes, the same recommen-
dation is being used. Figure 17 shows the configuration to test the interference margin for DS3/STS1. Figure
18 shows the set up for E3.
FIGURE 17. INTERFERENCE MARGIN TEST SET UP FOR DS3/STS-1
Sine Wave
N
Generator
Attenuator
∑
Pattern Generator ^S
2 ²³ -1 PRBS
DS3 = 22.368 MHz
STS-1 = 25.92 MHz
0 to 900 feet
Coaxial Cable
DUT
(XRT73L02M)
Test Equipment
FIGURE 18. INTERFERENCE MARGIN TEST SET UP FOR E3.
Noise Generator N
2 ²³ -1 PRBS
Attenuator 1
Attenuator 2
S
Signal Source
0 to 12 dB Cable Loss
∑
DUT
(XRT73L02M)
Test Equipment
MODE
E3
TABLE 9: INTERFERENCE MARGIN TEST RESULTS
CABLE LENGTH (ATTENUATION)
INTERFERENCE TOLERANCE
0 dB
- 17 dB
12 dB
-15 dB
27