DATA BULLETIN
MX128 Cordless Telephone Scrambler
Features
Full-Duplex Audio Processing
On-Chip Filters
Carrier Rejection >55dB
Uses IF (10.24 MHz) Clock
Requires No Extra Crystal
Excellent Audio Quality
Low Voltage 3.3V/5.0V Operation
ECPA* Qualified Voice Protection
Applications
Battery Powered Portability
Cordless Telephones
Wireless PBXs
TX Path
-
+
VBIAS
Inversion
Carrier
RX Path
-
+
VBIAS
The MX128 is a full-duplex frequency inversion scrambler designed to provide secure conversations for 46/49
MHz cordless telephone users. 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 MX128 uses mixed signal CMOS switched-capacitor filter technology and operates from a single supply
in the range of 3.0V to 5.5V. 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).
The MX128 is available in the following package styles: 16-pin SOIC (MX128DW) and 16-pin PDIP
(MX128P).
*Electronics Communications Privacy Act (Title 18, US Code 2510 et seq.)
©1998 MX-COM Inc.
www.mxcom.com Tel: 800 638-5577 336 744-5050 Fax: 336 744-5054
Doc. # 20480101.010
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All trademarks and service marks are held by their respective companies.