CMX866

V.22 bis Modem with AT Command Set


Features
  • V.22bis, V.22 and Bell 212A QAM/DPSK
  • V.23, Bell 202, V.21 and Bell 103 FSK
  • Integral AT Command Set with 'Fast Connect'
  • V.23 and Bell 202 'Fast Turnaround' Support for Type 1 Caller Line Identification
  • DTMF/Programmable Tones: Tx and Rx
  • 'Zero-Power' and 'Powersave' Standby Modes
  • DE8661 DemoKit and Reference Diagram Available
Applications
  • Telephone Telemetry Systems
  • Remote Utility Meter Reading
  • Security Systems
  • Industrial Control Systems
  • Electrical Cash Terminals and ATMs
  • Pay-Phones
  • Cable TV Set-Top Boxes
  • EPOS Terminals
Package Styles:
- CMX866D1  - CMX866D6
 
Supply Requirement:
2.7V power supply

Description
The CMX866 is a multi-standard modem for use in telephone based information and telemetry systems. Control of the device is via AT commands over a simple 9600b/s serial interface, compatible with most types of host µController. An RS232 compatible interface can be created by the addition of a Level Converter. The data transmitted and received by the modem is also transferred over the same serial interface. The on-chip µController interprets these AT commands and controls an internal DSP, which provides the modem and anciliary functions such as Ring Detection, Call Progress Detection, Hook Switch control and DTMF autodialling. User-specific DSP functions are also available via the AT command set.
Hardware support is provided for V.23 and Bell 202 Fast Turnaround and for rapid return to AT Command mode. A Fast Connect mode has been implemented to reduce modem connection time. 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. Complete examples of 2-wire line interfaces to an external host µC and to an RS232 interface, including the additional components required for Type 1 CLI, are provided. The device features a Hook Switch relay drive output and a Ring Detector circuit that remain operational when the CMX866 is in ‘Zero-Power’ or Powersave mode, providing an interrupt which can be used to wake up an external host µC, as well as the CMX866, when line voltage reversal or ringing is detected.
 

CMX866 multi-standard wireline modem with AT Command set