Datasheet

DS26504 T1/E1/J1/64KCC BITS Element
93 of 129
13.8 Recommended Circuits
Figure 13-4. Software-Selected Termination, Metallic 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
T1
T2
T3
T4
2:1
1:1
F1
F2
TX
TIP
TX
RING
RX
TIP
RX
RING
60 60
0.1 uF
10uF
Table 13-1. Component List (Software-Selected Termination, Metallic
Protection)
NAME DESCRIPTION
F1 and F2 1.25A slow blow fuse
S1 and S2 25V (max) transient suppressor
S3 andS4 77V (max) transient suppressor
Transformer 1:1CT and 1:136CT (5.0V, SMT) (Note 1)
T1 and T2
Transformer 1:1CT and 1:2CT (3.3V, SMT) (Note 1)
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:
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 3:
Some T1 (never in E1) applications source or sink power from the network-side center taps of the Rx/Tx
transformers.
Note 4:
A list of transformer part numbers and manufacturers is available by contacting
www.maxim-ic.com/support
.