Dual SPM Detector

The MX641 is a low-power, system-selectable Dual Subscriber Pulse Metering (SPM) Detector designed to indicate the presence, on a telephone line, of either 12kHz or 16kHz telephone call-charge frequencies. It is designed for PBX and PABX line-card and remote telephone installations. Under µProcessor control via a common serial interface, each channel of the MX641 will detect call-charge pulses from a telephone line and provide a digital output for recording, billing or security purposes. A common set of external components and a stable 3.579545MHz Xtal/clock input ensures that the MX641 adheres accurately to most national “Must and Must-Not” decode band-edges and threshold levels. For non-µProcessor systems a preset sensitivity/system input allows external channel level and system setting

FEATUREs
• Two (12kHz / 16kHz) SPM Detectors on a Single Chip
• Detects 12 or 16kHz SPM Frequencies
• ‘Controlled’ (µC) & ‘Fixed’ Signal Sensitivity Modes
• Selectable Tone Follower or Packet Mode Outputs
• High Speech-Band Rejection Properties
• ‘Output Enable’ Multiplexing Facility

APPLICATIONs
• Call Charge Applications on PABX Line Cards
• Remote Telephone Applications