CMX631A 12kHz and 16kHz Subscriber Pulse Metering (SPM) Detector IC

Features:

Low Power Operation
Detects 12kHz and 16kHz SPM Frequencies
High Speechband Rejection Properties
Tone Follower and Packet-mode Outputs

Applications:

Complex and/or Simple Telephone Systems
Hotel and Office Call-Charge/Logging Systems
Billing Systems
Public Call Monitoring
Payphone Systems
PCMCIA Fax and Data Modems

Packages:

CMX631AD4 - 16-pin SOIC
CMX631AD5 - 24-pin SSOP
CMX631AP3 - 16-pin PDIP

Supply Requirement:

3.0 to 5.5 V power supply

Description
The CMX631A is a low-power, system-selectable Subscriber Pulse Metering (SPM) detector to indicate the presence, on a telephone line, of both 12kHz and 16kHz telephone call-charge tone frequencies.

Deriving its input directly from the telephone line, input amplitude/sensitivities are component adjustable to the user’s national ‘Must/Must-Not Decode’ specifications via an on-chip input amplifier, whilst the 12kHz and 16kHz frequency limits are accurately defined by the use of an external 3.579545MHz telephone-system Xtal or clock-pulse input.

The CMX631A, which demonstrates high 12kHz and 16kHz performance in the presence of both voice and noise, can operate from either a single or differential analogue signal input from which it will produce two individual logic outputs.

This system (12kHz/16kHz) selectable microcircuit, which may be line-powered, is available in: 24-pin SSOP, 16-pin SOIC and 16-pin plastic DIP packages.

Block Diagram

CMX631A: a low-power, system-selectable Subscriber Pulse Metering (SPM) detector

12kHz and 16kHz SPM Detector