Datasheet

DS26504 T1/E1/J1/64KCC BITS Element
94 of 129
Figure 13-5. Software-Selected Termination, Longitudinal Protection
DS26504
DVDD
DVSS
TVSS
TVDD
RVSS
RVDD
0.01 uF 0.1 uF
68 uF
0.1 uF
0.1 uF
3.3 V
3.3 V
TTIP
TRING
RTIP
RRING
S1
S2
S3
S4
S5
S6
S7
S8
T1
T2
T3
T4
2:1
1:1
F1
F2
F3
F4
TX
TIP
TX
RING
RX
TIP
RX
RING
60 60
0.1 uF
10uF
Table 13-2. Component List (Software-Selected Termination, Longitudinal
Protection)
NAME DESCRIPTION
F1 to F4 1.25A slow blow fuse
S1 and S2 25V (max) transient suppressor (Note 1)
S3, S4, S5, S6 180V (max) transient suppressor (Note 1)
S7 and S8 40V (max) transient suppressor
Transformer 1:1CT and 1:136CT (5.0V, SMT) (Note 2)
T1 and T2
Transformer 1:1CT and 1:2CT (3.3V, SMT) (Note 2)
T3 and T4 Dual common-mode choke (SMT)
Note 1:
T3 and T4 are optional. For more information, contact the Telecom Support Group at www.maxim-ic.com/support.
Note 2:
A list of alternate transformer part numbers and manufacturers is available at www.maxim-ic.com/support
.
Note 3:
The layout from the transformers to the network interface is critical. Traces should be at least 25 mils wide and
separated from other circuit lines by at least 150 mils. The area under this portion of the circuit should not contain
power planes.
Note 4:
Some T1 (never in E1) applications source or sink power from the network-side center taps of the Rx/Tx
transformers.
Note 5:
The ground trace connected to the S2/S3 pair and the S4/S5 pair should be at least 50 mils wide to conduct the extra
current from a longitudinal power-cross event.