CPC5710N

8

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R03

3.2 Non-Intrusive Line Monitoring, Display Feature (Caller ID) Signal

Reception, and Ringing Detection Application

This application uses the logic input LIN/CMP to select

between ringing detection or buffering display feature

(caller-ID) and voice signals. Note the AC coupling of

the tip and ring signals.

With this circuit, setting LIN/CMP to a logic high

enables the ringing detector. After a valid ringing

period, configure LIN/CMP with a logic low to couple

the audio frequency signal to the output pins.

Please see “Detector Considerations” on page 5 for more

information on ringing detection.

Figure 5. Non-Intrusive Line Monitoring, Display Feature (Caller ID) Signal Reception, and Ringing

Detection Application Circuit

3.2.1 Frequency Response

The blocking capacitors used in this application circuit

affect the frequency response of the system. With the

components shown, response rolls off 3dB @ 166Hz.

Other values can be used for different response

characteristics.

3.3 Regulatory Issues

Component sizing and value recommendations shown

in the application circuits above will need to be

reviewed with regard to the regulatory and safety

requirements for each particular application.

RINGING DET

Display Feature Output

V

= V at 500 Hz

OUT

IN

3.3 or 5 V

U1 CPC5710

R1-4

1.8 M

Ω

C1,2

220 pF

R5

1.5M

0603

Ω

TIP

RING

From

Control

Logic

Unless noted otherwise:

1/8W,

All resistors are

1%, 1206.

50k

Ω

Switch shown

in Detector Mode

IN+

IN-

LIN/CMP

LINOUT+

LINOUT-

+

+

-

-

-

+

1.625 V

1.25 V

2 V

0 V

A=6

V

3

6

7

1

2

5

4

GND

8

GND

+

-

+

-

R1

C1

R2

R3

R4 C2

CMPOUT