XRT83L30_06 Datasheet, PDF (23/78 Pages) Exar Corporation – SINGLE-CHANNEL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR

XRT83L30
REV. 1.0.1 SINGLE-CHANNEL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
Once the T1/E1 input signal has been normalized to 0dB by adding the maximum gain (+29dB), the receiver
will declare RLOS if the signal is attenuated by an additional -9dB. The total cable loss at RLOS declaration is
typically -38dB (-29dB + -9dB). A 3dB hysteresis was designed so that transients will not trigger the RLOS to
clear. Therefore, the RLOS will typically clear at a total flat loss of -35dB. See Figure 7 for a simplified diagram.
FIGURE 7. SIMPLIFIED DIAGRAM OF -29dB T1/E1 GAIN MODE AND RLOS CONDITION
+3dB
-9dB
Normalized up to +29dB Max
Clear LOS
Declare LOS
+3dB
-9dB
Declare LOS
Clear LOS
Normalized up to +29dB Max
Setting the Receiver Input to -36dB T1/E1 Long Haul Mode
By setting the receiver input to -36dB T1/E1 long haul mode, the equalizer will detect the incoming amplitude
and make adjustments by adding gain up to a maximum of +36dB normalizing the T1 input signal. This setting
refers to cable loss (frequency), not flat loss (resistive). Once the T1/E1 input signal has been normalized to
0dB by adding the maximum gain (+36dB), the receiver will declare RLOS if the signal is attenuated by an
additional -9dB. The total cable loss at RLOS declaration is typically -45dB (-36dB + -9dB). A 3dB hysteresis
was designed so that transients will not trigger the RLOS to clear. Therefore, the RLOS will typically clear at a
total cable attenuation of -42dB. See Figure 8 for a simplified diagram.
FIGURE 8. SIMPLIFIED DIAGRAM OF -36dB T1/E1 LONG HAUL MODE AND RLOS CONDITION
+3dB
-9dB
Normalized up to +36dB Max
Clear LOS
Declare LOS
+3dB
-9dB
Declare LOS
Clear LOS
Normalized up to +36dB Max
E1 Extended RLOS
E1: Setting the Receiver Input to Extended RLOS
By setting the receiver input to extended RLOS, the equalizer will detect the incoming amplitude and make
adjustments by adding gain up to a maximum of +43dB normalizing the E1 input signal. This setting refers to
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