COMMUNICATION SEMICONDUCTORS
DATA BULLETIN
CMX673
Call Progress Tone Detector
PRELIMINARY INFORMATION
Features
• Worldwide Tone Compatibility
• Fast Response
Stutter Dial Tone
Single and Dual Tones
• Industry Compatible Pin Out
• Wide Dynamic Signal Range
• Low Power: 0.5mA at 3.0V
• 3.0V to 5.0V Operation
• 3.58MHz Xtal/Clock Oscillator
Applications
• Worldwide Payphone Systems
• Featurephone active feature confirmation
• Telephone Redialing Systems
• Dialing Modems
• Banking and Billing Systems
• Telecom Test Equipment
• Telecom Security Systems
ENABLE
LEVEL
DETECTOR
SIGNAL
INPUT
AMPLIFIER
SIGNAL
ANALYZER
CONTROL
AND
OUTPUT
LOGIC
CALL PROGRESS
DETECTOR
CALL
PROGRESS
DETECT
The CMX673 is a low voltage multi-purpose Call Progress Tone detector for use in Public Switched Telephone
Network System (PSTN) applications. Call progress detection allows equipment that dials into the PSTN to
monitor the progress of the resulting call. Various states such as Ringing, Busy, Not available, and Answer
can be determined. Using digital signal processing techniques the CMX673 accurately analyzes tones in the
315Hz to 650Hz frequency band and distinguishes valid call progress tone signals from line noise or voice.
This contrasts with other call progress detection devices that are based on simple filtering techniques. When
combined with cadence measurement of the CMX673 output, the rapid detect response time of the CMX673
allows it to support a wide range of call progress functions including ‘stutter dial tone’ detection used in voice
messaging systems.
A single, low cost 3.58MHz crystal ensures accurate and repeatable performance. With supply requirements
between 2.7V and 5.5V the CMX673 is easily integrated into a wide range of telecom applications.
The convenient CMX673 pin out allows it to be readily incorporated into existing product designs to quickly
achieve its benefits. Small geometry CMOS design techniques provide a complete call progress detector that
analyzes both frequency and amplitude in a small single package. Available packages are: 8-pin PDIP
(CMX673P1), 16-pin SOIC (CMX673D4), and 20-pin TSSOP (CMX673E3).
ã2001 MX-COM, Inc
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
Doc. # 20480182.007
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All Trademarks and service marks are held by their respective companies.