D/128/2 January 2003
• Full-Duplex Audio Processing
• On-Chip Filters
• Carrier Rejection >55dB
• Uses IF (10.24 MHz) Clock
• Excellent Audio Quality
• Low Power Operation (3.0V)
• Battery Powered Portability
• Cordless Telephones
• Wireless PBX
• Two-Way Radio
• Leisure Radio
(FRS, GMRS, MURS, PMR446)
1.1 Brief Description
The FX/MX128 is a full-duplex frequency inversion scrambler designed to provide secure conversations.
The Rx and Tx audio paths consist of the following:
1. A switched-capacitor balanced modulator with high baseband and carrier rejection.
2. A 3.3 kHz inversion carrier (injection tone).
3. A 3100 Hz lowpass filter.
4. Input op-amps with externally adjustable gain.
The FX/MX128 uses mixed signal CMOS switched-capacitor filter technology and operates from a single
supply in the range of 3.0 to 5.5 volts. The inversion carrier's frequency and filter switching clock are
generated on-chip using an external 10.24 MHz or 3.58/3.6864 MHz crystal or clock input (selectable).
This device is available in the following package styles: 16-pin SOIC,TSSOP and PDIP.
© 2003 CML Microsystems Plc