Family Radio CTCSS 'Type 2' Encoder and Decoder
CMX808A
1.7.1.3 Operating Characteristics
For the following conditions unless otherwise specified:
Xtal Frequency = 4.0MHz
Audio Level 0dB ref. = 308mVrms at 1kHz
V
DD
= 3.0V to 5.0V, Tamb = -40°C to +85°C.
Composite Signal = 308mVrms at 1kHz + 75mVrms Noise + 31mVrms Sub-Audio Signal
Noise Bandwidth = 5kHz Band Limited Gaussian
Notes Min.
Typ.
Max.
Units
DC Parameters
At V = 3.0V
DD
I
I
(powersaved)
(Encoder or Decoder only Operating)
2
2
-
-
0.2
1.3
0.3
2.0
mA
mA
DD
DD
At V = 5.0V
DD
I
I
(powersaved)
(Encoder or Decoder only Operating)
2
2
-
-
0.5
3.2
0.8
4.8
mA
mA
DD
DD
"C-BUS" Interface
Input Logic "1"
Input Logic "0"
Input Leakage Current (Logic "1" or "0")
Input Capacitance
70%
-
-1.0
-
90%
-
-
-
-
-
-
-
-
-
-
V
DD
30%
1.0
7.5
-
10%
10.0
V
DD
µA
pF
V
Output Logic "1" (I = 120µA)
OH
DD
Output Logic "0" (I = 360µA)
V
DD
OL
"Off" State Leakage Current (Vout = V
)
3
5
µA
DD
AC Parameters
CTCSS Decoder
Sensitivity
Response Time
De-Response Time
Frequency Range
(Pure CTCSS Tone)
(Composite Signal)
(Composite Signal)
-
-
-
-26.0
140
145
-
-
-
-
dB
ms
ms
Hz
60.0
251
CTCSS Encoder
Frequency Range
60.0
-
-
0
251
0.3
+1.0
-
Hz
%
dB
%
Tone Frequency Resolution
Tone Amplitude Tolerance
Total Harmonic Distortion
-
-1.0
-
1
3.0
Audio Band-Pass Filter
Passband
Passband Gain (at 1.0kHz)
Passband Ripple (w.r.t. gain at 1.0kHz)
Stopband Attenuation
Residual Hum and Noise
Alias Frequency
6
6
6
6
350
-
0
-
3000
Hz
dB
dB
dB
dBp
kHz
-
-2.0
30.0
-
-
+0.5
-
-
-
-
-50.0
62.5
-
Audio Attenuator
Nominal Adjustment Range
Attenuation Accuracy
Step Size
0
-1.5
-
-
-
48
1.5
-
dB
dB
dB
1.6
2003 CML Microsystems Plc
18
D/808A/6
CMLMICRO [ CML MICROCIRCUITS ]
