1200/2400/4800bps MSK Modem
14
MX469
Notes Min. Typ.
Max.
Units
Transmitter Output
TX Output Level
775
mV
RMS
Output Level Variation
1200/1800Hz
0
±1.0
±1.0
±1.0
5.0
dB
1200/2400Hz
0
dB
dB
%
2400/4800Hz
0
Output Distortion
3rd Harmonic Distortion
Logic ‘1’ Carrier Frequency
1200bps
3.0
2.0
3.0
%
6
6
6
1200
1200
2400
Hz
Hz
Hz
2400bps
4800bps
Logic ‘0’ Carrier Frequency
1200bps
6
6
6
1800
2400
4800
Hz
Hz
Hz
2400bps
4800bps
Isochronous Distortion
1200Hz - 1800Hz/1200Hz -
2400Hz
25.0
20.0
10.0
40.0
40.0
20.0
ꢄs
ꢄs
ꢄs
1800Hz - 1200Hz/2400Hz -
1200Hz
2400Hz - 4800Hz/4800Hz -
2400Hz
Operating Characteristics Notes:
1. With reference to V = 5.0 volts.
DD
2. Xtal frequency (ref. Clock Rate pin), type and tolerance depends upon system requirements.
3. See Figure 4 (variation of BER with Input Signal Level).
4. SNR = Signal-to-Noise in the Bit-Rate Bandwidth.
5. See Figure 2.
6. Dependent upon Xtal tolerance.
7. 10101010101 ...01 pattern.
8. Measured with a 150mV
input signal (no noise).
RMS
9. Reference (0dB) level for C.D. probability measurements is 230mV
.
RMS
10. For 1200bps and 2400bps operation only: when operating at 4800bps the carrier detect output should
be ignored.
ꢀ1998 MX-COM, Inc.
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
Doc. # 20480081.010
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