DS2149DK/DS21349DK T1/J1 Line Interface Unit Design Kit

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LINE-SIDE CONNECTIONS

The DS2149DK/DS21349DK implements the Tx and Rx line interface networks recommended in the DS2149 and

DS21349 data sheets and as shown in Figure 2. To connect the DS2149DK/DS21349DK to T1 or J1 test

equipment, connect the equipment to the RJ48 connector or to the two bantam connectors, J2 and J3. Please

notice the relays disconnecting TTIP and TRING on T1 and T2. These relays disconnect the series resistors R4

and R5, which is recommended for some long-haul configurations. Pin 16 on the system connector serves as the

control line for the relays. When pin 16 is high, T2 is enabled with TTIP and TRING. When it is held low, T1 is

enabled with TTIP and TRING.

Figure 2. Line-Side Circuitry

T3

J3

RECEIVE

R9

50

W

(1%)

R8

50

W

(1%)

RTIP

RRING

Dallas

Semiconductor

DS2149/DS21349

TTIP

TRING

TRANSMIT

J2

T2

T1

C2

1

mF

R4

4.7

W

(1%)

R5

4.7

W

(1%)