Features:
- Full Duplex Frequency Inversion Scrambling
- On-Chip Bandpass and Lowpass Audio Filters
- High Quality Audio Output
- Carrier Rejection >55dB
- Selectable Xtal/Clock Frequency: 10.24MHz or 3.58/3.6864MHz
Applications:
- Cordless Telephones
- Leisure Radio (FRS, GMRS, MURS and PMR446)
- Two-Way Radio
- Wireless PABX
- Base and Portable Systems
Packages:
- FX128D4 - 16-pin SOIC
- FX128E4 - 16-pin TSSOP
- FX128P3 - 16-pin PDIP
- MX128E4 - 16-pin TSSOP
Supply Requirement:
- 3.0 to 5.5 V power supply
Description
The FX/MX128 is a full-duplex frequency inversion scrambler designed to provide secure
voice conversations for 46/49 MHz cordless telephone users.
The Rx and Tx audio paths consist of the following:
- A switched-capacitor balanced modulator with high baseband and carrier rejection
- A 3.3kHz inversion carrier (injection tone)
- A 3100Hz lowpass filter
- 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 10.24MHz or 3.58/3.6864 MHz crystal or clock input (selectable).
FX/MX128 Audio Band Scrambler: Block Diagram
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