Icom IC-A22 Service Manual - page 9
3-4 POWER SUPPLY CIRCUITS
3 - 4
PIN
NO.
PORT
NAME
DESCRIPTION
2
LBATT
Input port for detecting the connected
battery (or external DC input) voltage for
"LOW BATT" or "OVER V" indication.
3
SQL
Input port for the squelch condition.
When squelch open: Low
4
LOK
Input port for the PLL condition.
When PLL in unlocked: High
14
CLK
Outputs a clock signal to the PLL IC
(IC4001).
15
DATA
Outputs N-data to the PLL IC.
16
ENB
Outputs a strobe signal to the PLL IC.
17
SCL
Outputs a clock signal to the EEPROM
(IC6002).
18
SDA
Outputs data to the EEPROM.
19
UP
Input port for the tuning dial "UP" clock.
20
DOWN
Input port for the tuning dial "DOWN" clock.
21
LIGHT
Outputs a backlit control signal for the
LCD and keypad. High: for lighting
22
BEEP
Outputs beep signals.
23
CLONE
Outputs clone data.
24
PTT
Input port for the PTT switch.
When PTT is pushed: High
25
CLONE
Input port for the clone reading.
26
BACK UP Input port for the CPU backup signal.
27
VORS*
Input port for the VOR reference signal.
28
VORC*
Input port for the VOR variable signal.
29
VORO*
Input port for the VOR level signal.
LINE DESCRIPTION
HV
Voltage line from the attached battery pack or the
[DC 12V] jack.
VCC
The same voltage as the HV line which is controlled
by [POWER] switch (R5052).
5V
Common 5 V converted from the VCC line by the
5V regulator circuit (Q5014, Q5015, D5005) using
the reference regulator (IC5006) on the MAIN unit.
+5
Common 5 V converted from the VCC line by the
+5 regulator circuit (Q5016, Q5017, D5006) using
5V line as the reference voltage.
R5
5 V for receiver circuit converted from the VCC line
by the R5 regulator circuit (Q5018, Q5019, Q5020,
D5007).
R5 is controlled by Q5018 using TRC signal from
the CPU(IC6001).
T+5
5 V for transmitter circuit controlled by the TMUT
signal from the CPU (IC6001). T+5 regulator circuit
is located on the RF unit and consists of Q4012,
Q4013 and D4016.
3-5 CPU PORT ALLOCATIONS
PIN
NO.
PORT
NAME
DESCRIPTION
30–
33
R10–R13 Output ports for the key matrix.
34–
37
R20–R30 Input port for the key matrix.
38–
41
R31–R33 Input port for the initial matrix.
42
WX
Outputs the WX control signal.
High: when a WX channel is selected.
43
NAV*
Outputs the navigation channel signal.
High: when a NAV channel is selected.
44
ANL
Outputs the ANL signal.
High: to activate the ANL function
46
AFON
Outputs the AF power amplifier control
signal.
High: to activate the amplifi er
47
TRC
Outputs a Tx/Rx control signal.
High: for Tx
48
TMUT
Outputs a Tx mute signal. Low: for muting
49
SHIFT
Outputs a "shift" signal for VCO oscillating
frequency.
Note: * for IC-A22/E only