CML Microcircuits
COMMUNICATION SEMICONDUCTORS
D/865/3 November 2005
CMX865
FSK Modem and
DTMF Codec
Provisional Issue
Features
•
V.23 1200/75, 1200/1200, 75, 1200 bps FSK
•
Bell 202 1200/150, 1200/1200, 150, 1200 bps FSK
•
Bell 103 300/300 bps FSK
•
Low Voice Falsing DTMF Decoder
•
DTMF/Tones Transmit and Receive
•
Low Power - High Performance
•
Software and Hardware Compatible with CMX86x
Family of Wireline Products
Applications
•
Wireless Local Loops
•
SMS Phones
•
Security Systems
•
Remote Utility Meter Reading
•
Industrial Control Systems
•
Pay-Phones
•
Set-Top Boxes
1.
Brief Description
The CMX865 is a multi-standard modem for use in telephone based information and telemetry systems.
Control of the device is via a simple high speed serial bus, compatible with most types of µC serial
interface. The data transmitted and received by the modem is also transferred over the same serial bus.
On-chip programmable Tx and Rx USARTs are provided for use with asynchronous data and allow
unformatted synchronous data to be received or transmitted as 8-bit words.
A high-quality DTMF decoder with excellent immunity to falsing on voice and a standard DTMF encoder
are included. Alternatively, these blocks can be used to transmit and detect user-specific, programmed
single and dual-tone signals, call progress signals or modem calling and answering tones.
Flexible line driver and receive hybrid circuits are integrated on chip, requiring only passive external
components to build a 2 or 4-wire line interface.
The device also features a Hook Switch Relay Drive output and a Ring Detector circuit which continues to
function when the device is in the powersave mode, providing an interrupt which can be used to wake up
the host µController when line voltage reversal or ringing is detected.
The CMX865 operates from a single 3.0 to 3.6V supply over a temperature range of -40°C to +85°C and
is available in a 24-pin SOIC package.
©
2005 CML Microsystems Plc
CMLMICRO [ CML MICROCIRCUITS ]
