This datasheet provides detailed information on the CMX661. The CMX661 is a low power, dual channel pulse metering (SPM) detector that can be used for the detection of 12kHz or 16kHz telephone call charge frequencies on a telephone line.
The CMX661 is a low power, Dual Subscriber Pulse Metering (SPM) Detector designed for pair-gain systems and out-of-band signalling applications in PBX and PABX line cards. It features two detectors on a single chip capable of detecting 12kHz or 16kHz telephone call charge frequencies with selectable bandwidth limits.
| Supply Voltage | 3.0V to 5.0V |
|---|---|
| Operating Current | ~750µA at 3V |
| Crystal Frequency | 3.579545MHz |
| Detected Frequencies | 12kHz or 16kHz |
| Package Types | 16-pin plastic DIL and SOIC |
The device detects either 12kHz or 16kHz telephone call charge frequencies.
The SYSTEM SELECT logic input sets the frequency: High (logic '1') selects 12kHz, and Low (logic '0') selects 16kHz.
The default detection frequency is 12kHz because the pin has an internal pullup resistor.