Datasheet

DS26503 T1/E1/J1 BITS Element

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13.8 Recommended Circuits

Figure 13-4. Software-Selected Termination, Metallic Protection

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