CMX868AE2

Overview

The CMX868AE2 is a low-power V.22 bis modem integrated circuit manufactured by CML Microcircuits, designed for telephone-based telemetry and information systems. It supports multiple standards including V.22 bis (2400/2400 bps QAM), V.22/Bell 212A (1200/1200 or 600/600 bps DPSK), V.23 (1200/75, 1200/1200, 75/1200 bps FSK), Bell 202 (1200/150, 1200/1200, 150/1200 bps FSK), and V.21/Bell 103 (300/300 bps FSK). The device operates on a single 2.7V to 5.5V supply with a typical operating current of 5.5 mA and functions within a temperature range of -40°C to +85°C. It features an integrated DTMF encoder/decoder, programmable Tx/Rx USARTs, and a high-speed serial C-BUS interface for control.

Feature Summary

• Multi-standard modulation support including QAM, DPSK, and FSK for various telecommunication protocols.
• Integrated flexible transmit and receive USARTs compliant with V.14 requirements.
• Built-in DTMF/Tone generator and detector with immunity to falsing on voice signals.
• On-chip line driver and receive hybrid circuits requiring only passive external components.

Applications

• Telephone Telemetry Systems
• Remote Utility Meter Reading
• Security Systems
• Industrial Control Systems
• Electronic Cash Terminals

Procurement Notes

Verify the specific package variant against the datasheet, as the CMX868A series is available in TSSOP-24, SOIC, and DIP packages. Confirm that the 'E2' suffix corresponds to the required environmental compliance specifications. Ensure the host microcontroller supports the C-BUS serial interface protocol for proper device initialization and data transfer.

Selection Notes

Select this component when a multi-standard modem solution is required for legacy telephone lines. It is suitable for designs needing integrated DTMF capabilities alongside standard modem functions. Consider the power consumption profile if battery operation is critical, noting the availability of a Powersave mode. Verify that the system voltage falls within the 2.7V to 5.5V operating range.

Part Context

The CMX868AE2 belongs to the CMX86X family of communication semiconductors from CML Microcircuits. This family focuses on low-power, multi-standard modem solutions for embedded applications. The device integrates complex modem functions into a single chip, reducing the bill of materials compared to discrete implementations.

Replacement Considerations

Direct substitutes include other variants within the CMX868A family, such as CMX868AD4 or CMX868AP4, which may differ primarily in package type (SOIC or DIP) rather than electrical function. Cross-family replacements are not directly documented; verify pinout and register compatibility before substituting with other modem ICs.