CTCSS Signalling Processor
FX818
Notes
Min.
Typ.
Max.
Units
Audio Band-Pass Filter
Passband
8
8
8
8
300
-
0
-
-
3000
Hz
dB
dB
dB
dBp
kHz
Passband Gain (at 1.0kHz)
Passband Ripple (w.r.t. gain at 1.0kHz)
Stopband Attenuation
Residual Hum and Noise
Alias Frequency
-
-2
33.0
-
-
+0.5
-
-
-
-50.0
63
-
Output Impedances
TX SUB-AUDIO OUT and (Enabled)
-
-
2.0
500
-
-
k
k
RX AUDIO OUT
(Disabled)
Rx Amp and Summing Amp
Open Loop Gain
(I/P = 1mV at 100Hz)
-
-
10
-
70.0
5.0
-
-
-
-
-
dB
MHz
MW
kW
Unity Gain Bandwidth
Input Impedance
Output Impedance
(at 100Hz)
(Open Loop)
6.0
Transmitter Modulator Drives:
Mod.1 Attenuator
Attenuation (at 0dB)
-0.2
-1.0
0
-
0.2
1.0
dB
dB
Cumulative Attenuation Error
(wrt attenuation at 0dB)
Output Impedance
3
3
4
-
-
600
15.0
-
-
W
kW
Input Impedance (at 100Hz)
Mod.2 Attenuator
Attenuation (at 0dB)
Cumulative Attenuation Error
(wrt attenuation at 0dB)
Output Impedance
-0.2
-0.6
0
-
0.2
0.6
dB
dB
-
600
-
W
General Purpose Timer
Timing Period Range
Count Interval
1
-
-
242
-
ms
ms
0.95
Xtal/Clock Input
Pulse Width ('High' or 'Low')
Input Impedance (at 100Hz)
Gain (I/P = 1mVrms at 100Hz)
40.0
10.0
20.0
-
-
-
-
-
-
ns
MW
dB
Notes:
1. At V = 5.0V only. Signal levels or currents are proportional to V
.
DD
DD
2. Not including any current drawn from the device pins by external circuitry.
3. Small signal impedance, at V = 5.0V and Tamb = 25°C.
DD
4. Timing for an external input to the XTAL/CLOCK pin.
5. With input gain components set as recommended in Figure 2.
6. IRQN pin.
7. From one tone to another tone.
8. See filter response (Figure 3).
9. Measured at MOD1 or MOD2 output.
ã 1997 Consumer Microcircuits Limited
23
D/818/4
CMLMICRO [ CML MICROCIRCUITS ]
