CMX683
CML Microcircuits
COMMUNICATION SEMICONDUCTORS
D/683/1 June 2002
Call Progress and
"Voice" Detector
Advance Information
Features
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Applications
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Detects Single and Dual Call Progress Tones
Worldwide Call Progress Tone Compatibility
"Voice" Detect Outputs (Fast and Slow)
Wide Dynamic Range with Low Falsing
Low Power Operation: 600µA at 3.0V typ.
3.58MHz Xtal/Clock Oscillator
Worldwide Payphone Systems
Telephone Redialling Systems
Dialling Modems
Banking and Billing Systems
Telecom Test Equipment
Telecom Security Systems
1.
Brief Description
The CMX683 is a general purpose Call Progress tone detector for use in monitoring the progress of calls
in Public Switched Telephone System (PSTN) applications. Dial Tone, Ringing, Busy and Not Available
states can be distinguished by using the host µC to qualify the cadence of the CP DETECT output. The
CMX683 uses advanced digital techniques to characterise valid Call Progress tones, unwanted tones, line
noise and voice or music signals. In contrast to Call Progress detection devices based on simple filtering
techniques, the CMX683 offers excellent sensitivity coupled with low false detection rates.
The response time of the CMX683 allows it to operate with almost any Call Progress system. In
particular the ‘stuttered dial tone’ of voice mail messaging systems is supported. The use of statistical
processing techniques, which analyse signal frequency, duration and amplitude, enable the CMX683 to
distinguish voice or music activity from DTMF or Call Progress signals. Separate outputs integrate the
"voice" activity over both shorter and longer periods, enabling payphone and other billing systems to
commence charging when a line connection has been established. A single 3.58MHz crystal ensures
accurate and repeatable performance. With supply requirements between 2.7V and 5.5V and a low
current consumption, the CMX683 can be easily integrated into a wide range of telecom equipments.
The CMX683 has a similar pinout to all commonly used Call Progress detectors and is available in DIP,
TSSOP or SOIC packages.
©
2002 CML Microsystems Plc
CMLMICRO [ CML MICROCIRCUITS ]
