CPC5710N Datasheet, PDF (6/10 Pages) Clare, Inc. – Phone Line Monitor (PLM) IC

INTEGRATED CIRCUITS DIVISION
With the application circuit in Figure 5., the series
capacitors serve to reduce the magnitude of the
high-amplitude, low-frequency ringing signals, while
making the ringing detection threshold of the
CPC5710N variable with the frequency of the ringing
signal. With the circuit as given, CMPOUT will change
states with a 15Hz ringing signal at approximately
48V_PEAK. For a 68Hz ringing signal, CMPOUT will
change states with a ringing signal amplitude of
approximately 11.5V_PEAK.
In applications where CPC5710N will be used only as
a ringing level detector, or if significant attenuation of
the amplified signal can be tolerated, the frequency
variability of the ringing detection threshold can be
reduced by increasing the value of the resistors and
capacitors in series with the input.
Application Note AN-117 Customize Caller ID Gain and
Ringing Detect Voltage Threshold is a spreadsheet for
trying different component values in this circuit for
LITELINK snoop circuit applications.
CPC5710N
2.4 Power Quality
CPC5710N works best with a clean power supply. To
clean up power supply noise, IXYS Integrated Circuits
Division recommends using a pi network on the V_DD
pin as shown in Figure 3., if needed.
Figure 3. Optional Power Supply pi Network
3.3 or 5 V
R100
10
C100
1
C101 ^FB100
10
600 Ω
200 mA ^A
A
To V_DD
Pin 1
Note: For lower-frequency noise, use a 220 H
inductor in series with R100.
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