Digital Circuits; Power Supply Circuits - Icom IC-F4029SDR Service Manual

4-4 DIGITAL CIRCUITS (DSP UNIT)
4-4-1 RECEIVING
The 450 kHz 2nd IF signal from the IF IC (MAIN-C UNIT;
IC9, pin 11) is applied to the DSP unit via the buffer (MAIN-C
UNIT; Q8). The applied 2nd IF signal is passed through the
anti-aliasing filter (FI1) to remove unwanted components.
The filtered 2nd IF signal is amplified at the IF amplifier
(IC7, pins 1, 3), and applied to the A/D converter (IC13,
pin 3) and converted into the digital IF data. The converted
digital IF data is applied to the DSP IC (IC10) as a clock
synchronizer digital signal.
The digital-processed digital audio signal from the DSP IC
(IC10) is applied to the linear codec (IC16) and converted
into the analog audio signals, then applied to the AF mixer
(MAIN-C UNIT; Q36, Q37).
• DIGITAL CIRCUITS BLOCK DIAGRAM
RECEIVED SIGNAL
From FM IF IC
(IC9, pin 11)
To D/A converter
(IC12, pin 9)

4-5 POWER SUPPLY CIRCUITS

Voltage from the attached battery pack is routed to whole of the circuit in the transceiver via a switch and regulators.
• MAIN-C UNIT
Drive amplifier (Q702),
Power amplifier (Q701), etc.
CPU (IC22),
EEPROM (IC10),
Reset IC (IC8), etc.
LED backlight driver (Q45),
LCD driver (IC20),
D/A converter (IC12), etc.
S5V
PLL IC (IC2),
VCO's, etc.
T5V
Transmit circuits
R5V
Receive circuits
BPF
Buffer
AMP
IC7
Q18
FI1
AMP
TX SW
IC7
IC9
IC17
CPU5
CPU5V
regurator
+5V
+5V
regurator
Q26–Q28
Q23
S5V
regurator "S5C"
22
Q24, Q49
T5V
regurator
"T5C"
87
Q25
R5V
"R5C"
regurator
88
4-4-2 TRANSMITTING
The MIC signals from the AF mixer (MAIN-C UNIT; IC5, pin 7)
are applied to the linear codec (IC16, pin 2) and converted
into the digital audio data. The converted digital audio data
is applied to the DSP IC (IC10).
The processed digital audio signal from the DSP IC (IC10)
is applied to the linear codec (IC16) again, then converted
into the GMSK base band signal. The converted base band
signal is passed through the two-staged LPF (IC8, pins 6, 7
and pins 1, 3) and TX switch (IC9, pins 1, 2), then applied to
the D/A converter (MAIN-C UNIT; IC12, pin 9) via the buffer
amplifier (MAIN-C UNIT; IC7, pins 6, 7).
DSP UNIT
IC16
IC10
DSP
A/D
IC
LINER
IC13
CODEC
IC
LPF
AMP
IC8
IC8
Power switch F701
(PA-C unit)
VCC
R315
Battery pack
"PWON"
8
(IC22)
CPU
Voltage line
Control signal
4 - 5
AF
To AF cricuits
MIXER
Q36, Q37
From
AF
Analog switch
MIX
(IC3)
IC5
TRANSMIT SIGNA
• DSP UNIT
IC1
+5V
regurator
IC4
+3.3VA
+3.3V_A
regurator
IC2
+3.3V
+3.3V_VDD
regurator
IC3, D1
DC-DC
+1.35V_VDD
1.35V
+5V
VCC