CPC5710N Datasheet, PDF (6/9 Pages) Clare, Inc. – Phone Line Monitor (PLM) IC

CPC5710N
2.2 Non-Intrusive Line Monitoring, Display Feature (Caller ID) Signal
Reception, and Ring Detection Application
This application uses the logic input LIN/CMP to select
between detecting ringing or passing through display
feature (caller-ID) and voice signals. Note the AC
coupling of the tip and ring signals.
With this circuit, set LIN/CMP high to detect ringing.
After a valid ring, set LIN/CMP low to couple the audio
channel signal to the output pins.
Please see “Comparator Considerations” on page 7 for
more information on ringing detection.
Figure 4. Non-Intrusive Line Monitoring, Display Feature (Caller ID) Signal Reception, and Ring Detection
Application Circuit
From
Control
Logic
TIP
RING
U1 CPC5710
LIN/CMP
R1-4
(R_SNP)
1.8 M
R5
C1,2 (R_SNPD)
(C_SNP) 1.5 M, 1%
220 pF 0603
V_DD
IN+
IN-
+
1.625 V
-
-
+
A_V=6
V_DD
V_DD
CMPOUT
3.3 or 5 V
RING DETECT
(to ring parser)
Display Feature Output
LINOUT+
V_OUT = V_IN at 500 Hz
0V
2V
LINOUT-
V_SS
+
1.25 V
-
V_SS
V_SS
Unless noted otherwise:
All resistors are 1/8 W, 1%, 1206.
All capacitors are 2 kV, 10%.
A
2.2.1 Frequency Response
The blocking capacitors used in this application circuit
affect the frequency response of the system. With the
components shown, response rolls off 3 dB @ 166 Hz.
Other values can be used for different response
characteristics.
2.3 Regulatory Issues
Component sizing and value recommendations shown
in the application circuits above will need to be
reviewed with regard to the regulatory requirements of
any particular application.
6
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Rev. 1.0 12/16/2002