XRT59L91 Datasheet, PDF (15/28 Pages) Exar Corporation – Single-Chip E1 Line Interface Unit

RxPOS
RxNEG
Loss of Signal
U1
6
RxPOS
7
RxNEG
8
RxLOS
Preliminary
9
R T IP
10
R R in g
RL
30.1
XRT59L91
1 ^1:2 5
4
8
PE-65835
R T IP
R R IN G
XRT59L91
Figure 8. Recommended Schematic for Interfacing the Receive Section of the XRT59L91
Device to the Line for 120W Applications (Transformer-Coupling)
Note:
Figures 7 and 8 indicate that the user should use a “2:1
STEP-DOWN” transformer, when interfacing the re
ceiver to the line.
RxPOS
U1
6
RxPOS
9
R T IP
C1
1
2
0.1uF
1 ^R1 2
37.4
R T IP
RxNEG
Loss of Signal
7
RxNEG
8
RxLOS
R2
37.4
10
R R in g
C2
1
2
0.1uF
R R IN G
XRT59L91
Figure 9. Recommended Schematic for Interfacing the Receive Section of the XRT59L91
Device to the Line for 75W Applications (Capacitive-Coupling)
Rev. P2.00
15