CPC5601

R04

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2.1 Application Circuit Configurations

Figure 4 shows LITELINK II in circuit designed to use

the optical snoop circuit in the CPC5601 for ring

detection. Figure 5 shows LITELINK III in a circuit that

uses the LITELINK snoop circuit ring detection and

display feature (caller ID) signal processing. Note that

either generation of LITELINK can be used with either

signal monitoring scheme. Using the optical path on

the CPC5601 for ring detect precludes on-hook dis-

play feature signal processing.

2.2 AC Termination

2.2.1 LITELINK II

The networks connected to outputs b1, b2, b3 and b4

provide selectable telephone line AC termination

depending on which network is switched in place of

mation).

In North American applications, turn outputs b1 and

b2 on, and turn outputs b3 and b4 off to switch in the

required 600

 AC termination. For European applica-

tions, turn outputs b1 and b2 off, and outputs b3 and

b4 on to switch in the complex AC termination net-

work.

2.2.2 LITELINK III

The networks connected to outputs b1 and b3 provide

selectable telephone line AC termination depending

appropriate LITELINK data sheet and the application

note Understanding LITELINK for more information). The

resistor connected to output b2 provides the required

bias current for North American applications.

In North American applications, turn outputs b1 and

b2 on, and turn output b3 off to switch in the required

600

 AC termination. For European applications, turn

outputs b1 and b2 off, and output b3 on to switch in the

complex AC termination network.

2.3 LITELINK III Gain

Turning output 5 on adds attenuation to the receive

path, which is required for the complex termination.

Asserting the MODE pin on LITELINK III corrects for

the added attenuation.

2.4 Current Limiting

Clare recommends using the default value for RZDC

to set the loop-current limit to 133 mA. You can, if

required, adjust the current limit level by adding R73

and using output b6 to switch this value in parallel with

RZDC. See the appropriate LITELINK datasheet for

more information on setting loop-current limits.