Call Progress Tone Detector
Worldwide Tone Compatibility
Single and Dual Tones Detected
Wide Dynamic Signal Range
Fast Response Time
Low Power (Line) Operation
3.58MHz Xtal/Clock Oscillator
'Output Enable' Multiplexing Facility
Worldwide Payphone Systems
Telephone Redialing Systems
Banking and Billing Systems
Telecom Test Equipment
Telecom Security Systems
2.7 to 5.5 V power supply
The CMX673 is a general purpose call progress tone detector for use in Public Switched Telephone System (PSTN) applications.
Call progress detection allows equipment which dials into the PSTN network to monitor the progress of the resulting call: Ringing, Busy, Not Available and Answer states can be determined.
The CMX673 uses advanced digital signal processing techniques to detect tones in the frequency band 315 to 650 Hz. The use of DSP techniques allows the CMX673 to distinguish between valid call progress tone signals and line noise or voice, low false detection rates result.
This is in contrast to other call progress detection devices which are based on simple filtering techniques.
The detection timing of the CMX673 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 digital processing and small geometry CMOS design techniques allows the CMX673 to offer a complete call progress detector which analyses both frequency and amplitude in a single 8 pin (PDIP) package.
This, coupled with industry-leading performance and substantially lower power supply requirements than comparable devices, demonstrates CML’s unique capability in this area.
Design Support Information
|CMX673: Suggested Applications
||The CMX673 is an 8-pin DIP or 16-pin SOIC signal-detector that operates on energy in the frequency band of about 315 to 650 Hz. Its primary use is in the detection of status tones encountered during the progression of a telephone call. These tones include: dial tone, circuits busy, ring tone, station busy and others. Call status is derived by examining the cadence of those tones.