Specification ......
Characteristics
See Note
Min.
-
0
-
-
-
-
-
-
-
-
-
-
Typ.
775
-
3.0
2.0
1200
1200
2400
1800
2400
4800
25.0
20.0
-
Max.
-
±1.0
5.0
3.0
-
-
-
-
-
-
40.0
30.0
10.0
Unit
mVrms
dB
%
%
Hz
Hz
Hz
Hz
Hz
Hz
µs
µs
20 µs
Transmitter Output
Tx Output Level
Output Level Variation
1200/1800Hz or 1200/2400Hz or 2400/4800Hz
Output Distortion
3rd Harmonic Distortion
Logic ‘1’ Carrier Frequency
1200 Baud
6
2400 Baud
6
4800 Baud
6
Logic ‘0’ Carrier Frequency
1200 Baud
6
2400 Baud
6
4800 Baud
6
Isochronous Distortion
1200Hz - 1800Hz/1800Hz - 1200Hz
1200Hz - 2400Hz/2400Hz - 1200Hz
2400Hz - 4800Hz/4800Hz - 2400Hz
Notes
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
With reference to V
DD
= 5.0 volts.
Xtal frequency, type and tolerance depends upon system requirements.
See Figure 5 (variation of BER with Input Signal Level).
SNR = Signal-to-Noise Ratio in the Bit-Rate Bandwidth.
See Figure 2.
Dependent upon Xtal tolerance.
10101010101 ...01 pattern.
Measured with a 150mVrms input signal (no noise); 1200/2400 baud operation.
Reference (0dB) level for C.D. probability measurements is 230mVrms.
For 1200 and 2400 baud operation only; when operating at 4800 baud the Carrier Detect output
should be ignored.
1 x 10
-1
*
BIT RATE BANDWIDTH
1 x 10
-2
BIT ERROR RATE
10
dB
12
dB
SN
R
*
SN
R
*
1 x 10
-3
dB
20
R
SN
1 x 10
-4
*
1 x 10
-5
50
100
150
200
250
300
500
700
800
INPUT SIGNAL LEVEL (mVrms)
Fig.6 Typical Variation of Bit Error Rate with Input Level
7
CMLMICRO [ CML MICROCIRCUITS ]
