8
KDS-100
6. Transmit/Receive Signal Flow
■
Receive data signal
The transceiver detection output passes through CN5
No. 3 pin and amplifier (IC15), and its level is adjusted by the
D/A converter (IC17). The resulting signal is amplified by the
amplifier (IC22), goes to the CODEC (IC20), and is converted
to digital data.
This data is transferred serially from the CODEC to the
DSP (IC23) and operated by the DSP.
IC15
NJM2904M
AMP
SB
SBO
DI
GND
DO
PTT
DTC
SQ
TXS
AM
MM
ID
DISPOFF
TXD
RXD
MIC
DI
CN5
1
15
IC21
NJM2904M
AMP
SP
CN17
IC34
TDA7053AT
AUDIO AMP
Q10
2SB798
(DL,DK)
5V
AMP SW
1
2
+
–
DO
IC17
M62364FP
ELE-VOL
DI
MIC
DO
BUZZER
IC20
AK4550VT
CODEC
IC22
NJM2904M
AMP
IC14
NJM2904M
AMP
BUZZER
Q7
2SC4617
Q8
2SB1132
LED
DIMMER
IC23
TMS320VC5402PGE
IC19
TC74VHC4040FT
COUNTER
DSP
X2
12.288MHz
DSPCLK
EXT SP
CN18
1
2
+
–
■
Transmit data signal
The digital data processed by the DSP is transferred seri-
ally from the DSP to the CODEC, and converted to an analog
signal. It is amplified by the amplifier (IC14), its level is ad-
justed by the D/A converter (IC17), the signal passes
through the buffer amplifier (IC21), passes through CN5
No.5 pin, and is output to the transceiver as a transmit data
signal.
Fig. 9
CIRCUIT DESCRIPTION
