Description
The CPC5712 is a special purpose Phone Line Monitor with Detectors (PLMD) 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.

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-Lead 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