CTCSS Signalling Processor
FX818
Operating Characteristics
For the following conditions unless otherwise specified:
Xtal Frequency = 4.032MHz
Audio Level 0dB ref = 308mVrms at 1kHz
V
DD
= 3.3V 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 = 3.3V
DD
I
I
I
I
(powersaved, V = 5.0V)
1, 2
1, 2
1, 2
1, 2
-
-
-
-
0.6
0.35
3.5
1.0
0.6
6.0
2.5
mA
mA
mA
mA
DD
DD
DD
DD
DD
(powersaved, V = 3.3V)
DD
(Tx/Rx Operating V = 5.0V)
DD
(Tx/Rx Operating V = 3.3V)
1.6
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
V
DD
µA
pF
Output Logic "1" (I = 120µA)
V
DD
OH
Output Logic "0" (I = 360µA)
V
DD
OL
"Off" State Leakage Current (Vout = V
)
6
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
253
CTCSS Detector - Fast Detect
Sensitivity
Response Time
Frequency Range
(Pure CTCSS Tone)
(Composite Signal)
5
-
-
60
-26.0
56.0
-
-
dB
ms
Hz
253
CTCSS Detector - Fast Predictive
Sensitivity
(Pure CTCSS Tone)
(Composite Signal)
5
7
-
-
60
-
-26.0
37.0
-
-
dB
ms
Hz
Hz
Response Time
Frequency Range
Decode Bandwidth
-
253
-
40
CTCSS Encoder
Frequency Range
60
-
-
0
253
0.3
+1.0
-
Hz
%
dB
%
Tone Frequency Resolution
Tone Amplitude Tolerance
Total Harmonic Distortion
-
-1.0
-
1
9
2.0
ã 1997 Consumer Microcircuits Limited
22
D/818/4
CMLMICRO [ CML MICROCIRCUITS ]
