CMX625
ISDN TA POTS Interface
D/625/2 July 2001
Advance Information
Features
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SPM and Ringing Voltage Generators
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Integrated DTMF Decoder/Encoder
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V.23/Bell 202 FSK/Tone Generator
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Selectable A-Law/µ-Law PCM Codec
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IOM-2 Interface Terminal Mode and
Non-Terminal Mode (Line Card Mode)
Applications
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ISDN NTUs with Analogue Ports
•
ISDN Line Cards
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Wireless Local Loop Termination Cards
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ISDN Terminals with Additional POTS Ports
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PC based ISDN Cards with Telephone Ports
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Billing/SPM Systems
IOM is a trademark of Siemens AG
1.1
Brief Description
The CMX625 is an integrated telecom tone generator, DTMF encoder/decoder and PCM Codec-Filter
designed for ISDN interfaces, Wireless Local Loop and other digitised speech systems. The tone
generator covers a wide range of pre-programmed tones used in analogue phone systems. Three outputs
are provided: Ringing signals, In-band tones or FSK data, and 12kHz/16kHz Subscriber Metering pulses.
The PCM Codec-Filter performs voice digitisation and reconstruction and incorporates band limiting and
smoothing with selectable A-law or µ-law companding following ITU-T recommendation G.711. The
DTMF decoder presents the serial bus interface with the DTMF dialling information received from the
telephone user and the tone generator sends the appropriate DTMF tones to this POTS interface. Other
tone standards supported are: Fax and Modem ‘answer’ and ‘originate’, ITU-T ‘R1’ and ‘R2’ signals, dual
tones for CIDCW and 'On-Hook' signalling systems and sufficient tones for simple melody generation.
The IOM -2 (ISDN Oriented Modular revision 2) industry standard serial bus provides the digital interface
to other telecommunications ICs and supports both Terminal and non-Terminal (or Line Card) modes.
The CMX625 is compatible with the CMX635 ISDN Subscriber Processor and can be used to provide the
additional POTS port. It is available in both DIP and SSOP packages.
®
2001 Consumer Microcircuits Limited
CMLMICRO [ CML MICROCIRCUITS ]
