Power Supply Circuits; Port Allocations - Icom IC-R3 Service Manual

4-4 POWER SUPPLY CIRCUITS

VOLTAGE LINE
LINE DESCRIPTION
BATV The voltage from the attached battery.
VCC The same voltage as the BATV line (battery volt-
HV age).
Common 3V converted from VCC line by the
+3V converter circuit (LOGIC unit; Q6, Q39)
+3V
using the "POWERC" signal from the CPU
(LOGIC unit; IC11, pin 28).
Common 3V converted from the VCC line by the
+3V regulator circuit (LOGIC unit; IC3).
3V
The output voltage is applied to the RESET cir-
cuit (LOGIC unit; IC5, pin 2).
Receive 3V controlled by the R3V regulator cir-
R3V
cuit (LOGIC unit; Q4, Q5) using the +3SC signal
from the CPU (LOGIC unit; IC11, pin 27).
Common 4.5V converted from the VCC line by
the DC-DC converter (LOGIC unit; IC801).
4.5V
The output voltage is applied to the TFT driver
(LOGIC unit; IC901) and the TFT back light dri-
ver (LOGIC unit; Q821).
Common 5V converted from the VCC line by the
DC-DC converter (LOGIC unit; T1).
5V
The output voltage is applied to the OSD IC
(LOGIC unit; IC902), etc.
Common 12V converted from VCC line by the
DC-DC converter (LOGIC unit; T1).
12V
The output signal is applied to the TFT driver
(LOGIC unit; IC901).
Common 15V converted from the VCC line by
the DC-DC converter (LOGIC unit; T1).
15V
The output signal is applied to the TFT LCD
(LOGIC unit; DS54).

4-5 PORT ALLOCATIONS

4-5-1 EXPANDER IC (RF UNIT; IC5)
Pin Port
number name
5 B1C
6 B2C
7 B3C
8 65MC
9 30MC
10 SHIFT
11 DBL1
12 DBL2
16 470MC
17 600MC
4 - 8
Description
Outputs low-pass filter select signal.
Low : When frequencies 0.5 to 1.9
MHz are displayed.
Outputs bandpass filter select signal.
Low : When frequencies 1.9 to 15
MHz are displayed.
Outputs bandpass filter select signal.
Low : When frequencies 15 to 30
MHz are displayed.
Outputs bandpass filter select signal.
Low : When frequencies 65 to 108
MHz are displayed.
Outputs bandpass filter select signal.
Low : When frequencies 30 to 65
MHz are displayed.
Outputs control signal for the VCO shift
circuit (VCO unit; Q21, D61).
High : While the 1st VCO is shifting.
Outputs control signal for the doubler1
circuit (RF unit; Q26, D65, D67).
Outputs control signal for the doubler2
circuit (RF unit; Q26, D66, D68).
Outputs low-pass and bandpass filters
select signal.
Low : When frequencies 470 to 600
MHz are displayed.
Outputs low-pass and bandpass filters
select signal.
Low : When frequencies 600 to 750
MHz are displayed.