Features
• CPC5712 Outputs:
• Two Independent Programmable Level Detectors
with Programmable Hysteresis
• Fixed-Level Polarity Detector with Hysteresis
• Differential Linear Output
• Minimum External Components
• Excellent Common-Mode Rejection Ratio
(CMRR) > 55dB
• Application circuits meet isolation requirements of
worldwide telephony standards
• Worldwide telephone network compatibility
• Single Supply Operation, 3.0V to 5.5V
• High differential input impedance
• Very low common-mode input impedance
• Fixed Gain
• TTL Compatible CMOS Logic Level outputs
• Small SOP 16-Pin package

Applications
• VoIP Gateways, IP-PBX, xDSL
• TIP/RING Monitoring
• Line-In-Use Detection
• Polarity Detection for Caller ID, Enhanced 911
• Battery Detection, PSTN Check
• Non-telephony voltage level detection applications
• Instrumentation
• Industrial Controls

Description
The CPC5712 is a special purpose Voltage Monitor
with Detectors integrated circuit that is used in various
high-voltage telephony applications such as VoIP
gateways and IP-PBXs. The device monitors the
TIP/RING potential through a high-impedance divider
(resistor isolation) to derive two programmable signal
level detects, polarity information, and a scaled
representation of the phone line voltages. In use, the
resistor divider and the high input impedance of the
CPC5712 make the circuit practically undetectable on
the line.
The two voltage-level detects are programmed with
external resistors, which gives the designer complete
freedom with respect to line voltage detection levels.
The level settings also have programmable hysteresis
to prevent false triggering conditions. Detection of
these levels allows the user to determine the condition
of the line.
This device can also be used in non-telephony
applications such as instrumentation and industrial
controls, especially when a low-level differential level
needs to be detected in the presence of a large
common-mode voltage.