CML Semiconductor Products
SPM and Security Subsystem
1.0
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FX651
D/651/4 September 1997
Provisional Information
Features
Two Integrated Telecoms
Functions:
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Low Power (3.3V) Requirement
Component Adjustable Input
Sensitivity
Meets European 12kHz SPM
Frequency Specifications
Worldwide Pay-Phone
Applications
12kHz SPM Detector
Half Duplex 18kHz Modem
Compact 16-pin Small Outline
(SOIC) Package
Card Operated Telephone
Installations
V
BIAS
1.1
Brief Description
The FX651 integrated circuit combines 12kHz Subscriber Private Metering (SPM) detection with 18kHz
tone processing for anti-fraud purposes within a telephone system. This compact, low power device is
suitable for battery or line powered systems. Under simple logic or
µProcessor
control it will:
Decode 12kHz SPM pulses in the presence of high level voice and 18kHz signalling, and
provide a logic output.
Transmit an NRZ modulated 18kHz security tone to line.
Decode an incoming modulated 18kHz security tone in the presence of high level voice
and 12 kHz SPM tones, and provide a logic output.
Employing high accuracy switched capacitor filters, the FX651 is protected from crosstalk and false
decoding.
©
1997 Consumer Microcircuits Limited
CMLMICRO [ CML MICROCIRCUITS ]
