Brief Description
The FX631 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 frequencies.

FEATUREs
Detects 12kHz and 16kHz SPM Frequencies
Low Power (3.0 Volt_MIN <1.0mA) Operation
High Speechband Rejection Properties
Tone-Follower and Packet Mode Outputs

Applications
Complex and/or Simple Telephone Systems
Call-Charge/-Logging Systems