CMX673E3

Telecom Overview

The CMX673E3 is a call progress tone detector manufactured by CML Micro, designed for Public Switched Telephone System (PSTN) applications. It utilizes advanced digital signal processing to detect single and dual tones within the 315Hz to 650Hz frequency band. The device operates on a supply voltage between 2.7V and 5.5V, with a typical current consumption of 0.5mA at 3.0V. It features an internal oscillator requiring a 3.58MHz crystal and provides a logic output upon detection. The component is housed in an 8-pin TSSOP package.

Telecom Feature Summary

• Employs stochastic signal processing techniques to distinguish valid call progress tones from voice or line noise, ensuring low false detection rates compared to simple filtering methods.
• Supports worldwide tone compatibility by detecting standard single and dual frequencies used in global telecommunications networks.
• Features fast response time and wide dynamic signal range, allowing operation with various call progress systems including stuttered dial tones.

Telecom Applications

• Public Switched Telephone System (PSTN) monitoring equipment
• Worldwide payphone systems
• Telephone redialling systems
• Banking and billing systems

Telecom Procurement Notes

Verify the specific package type against the ordering suffix, as the E3 designation corresponds to the TSSOP-8 variant. Confirm that the required external components, such as the 3.58MHz crystal and decoupling capacitors, are included in the bill of materials. Ensure the design accommodates the 80ms initialization delay before the DETECT output becomes valid after power-up.

Telecom Selection Notes

Select this component when high reliability in noisy environments is required due to its DSP-based analysis rather than basic filtering. It is suitable for designs needing pin-to-pin replacement for legacy M980 or TSC75T980 devices. Consider the 2.7V to 5.5V operating range for flexibility in power supply design. Verify that the application requires detection within the 315Hz to 650Hz band.

Telecom Part Context

The CMX673 series represents a family of general-purpose call progress tone detectors developed by CML Microcircuits. The E3 suffix specifically identifies the surface-mount TSSOP-8 package version. This part belongs to the broader category of telecom interface ICs designed for PSTN signaling analysis. Other variants in the series include DIP and SOIC packages, offering different form factors for similar functionality.

Telecom Replacement Considerations

The CMX673 is pin-to-pin compatible with the M980, TSC75T980, and SSI980. When substituting these parts, verify that the replacement supports the same 3.58MHz clock requirement and voltage range. Ensure the new component meets the specific package constraints if space is limited.