CMX838 View Datasheet(PDF) - CML Microsystems Plc
Part Name
Description
MFG CO.
'CMX838' PDF : 71 Pages View PDF
FRS/PMR446/GMRS Family Radio Processor
CMX838
Examples of ‘RX from discriminator’, ‘TX voice from microphone’ and ‘TX internally generated audio tone with
loudspeaker enabled’ paths are illustrated in Figure 28, Figure 29, and Figure 30.
MICOUT 3
MICIN 4
-
+
Vbias
AUX I/O 2
RXIN 1
from the
discriminator
preemph
LPF
HPF
BOUT AOUT
27 28
AIN
BIN
25 24
LIM
voltage ref
RX volume control to
loudspeaker path
RXOUT 23
deemph
LPF
processed TX audio to
modulation section
Figure 28: Example Audio RX Path
MICOUT 3
MICIN 4
-
audio from an external
+
electret mic or a higher
level signal source Vbias
AUX I/O 2
alternate audio input e.g.
call tone signals
RXIN 1
from the
discriminator
preemph
LPF
alternate external audio processing paths
e.g. companding, scrambling, etc.
AOUT to AIN and BOUT to BIN
BOUT AOUT
27 28
AIN
BIN
25 24
HPF
LIM
voltage ref
RX volume control is
muted or disabled
RXOUT 23
deemph
LPF
processed TX audio to
modulation section
Figure 29: Example Audio TX Voice Path
MICOUT 3
MICIN 4
-
+
Vbias
AUX I/O 2
alternate audio input e.g.
call tone signals
RXIN 1
from the
discriminator
preemph
LPF
audio tone from Tone
Signaling Processor
alternate external audio processing paths
e.g. companding, scrambling, etc.
AOUT to AIN and BOUT to BIN
BOUT AOUT
27 28
AIN
BIN
25 24
HPF
LIM
voltage ref
processed TX tone audio to
loudspeaker path so user hears
own transmitted audio call tone
(RX volume control is not muted)
RXOUT 23
deemph
LPF
processed TX tone audio to
modulation section
Figure 30: Example Audio TX Internally Generated Tone with Loudspeaker Enabled Path
2003 CML Microsystems Plc
49
D/838/8
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