M-984-02
Special Information Tone Detector
Description
Features
The M-984-02 Special Information Tone Detector is a
monolithic integrated circuit designed to provide reli-
able detection of many common telephone network
status signals. In particular, it detects the signals
known as Special Information Tones (SITs) or error
tones as defined by the CCITT, and single tones often
used as dial tone, audible ringing, and other general
progress indications. The M-984-02 uses CMOS
switched capacitor filters and a crystal time base to
achieve the high stability and accuracy specified. Each
tone detection window has an associated output pin,
which can be placed in a high impedance state for use
with time-share microcomputer bus applications.
• Detects single-frequency tones used for error
indication and call progress in telephone systems
• Provides detection windows for:
400/425 Hz (Call Progress)
950 Hz (Special and error indication)
1400 Hz (Special and error indication)
1800 Hz (Special and error indication)
• Separate tri-state outputs for each tone window
• Inexpensive 3.58 MHz crystal time base
• Auxiliary 3.58 MHz clock output
• 14-pin DIP package and 16-pin SOIC package
• Single supply 3 to 5 volt (low power CMOS)
• Wide dynamic range (30 dBm)
In comparison with the earlier M-984, the M-984-02
has wider acceptance bands for SIT tones to facilitate
reception of tape-loop tones, lower power consump-
tion at 5V operation, 3V operation, superior tempera-
ture performance, lower cost, and is available in DIP,
SOIC, and SOIC tape and reel versions.
Applications
• Automatic dialers
• Modems
• Telecom test equipment
• Telephone traffic measurement,
• Service evaluation
• Billing equipment
Ordering Information
Part #
Description
14-pin plastic DIP
16-pin plastic, SOIC
16-pin SOIC, Tape and Reel
Pin Diagram
M-984-02P
M-984-02S
M-984-02T
Block Diagram
DS-M984-02-R3
1
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