MX128

CML Microcircuits COMMUNICATION SEMICONDUCTORS FX/MX128 Audio Band Scrambler D/128/2 January 2003 Provisional Information Features 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 Applications 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 c...