Icom IC-7000, Service Manual, Page: 14 / 92

3-5-2 MAIN UNIT VOLTAGE LINE
Line Description
3.3 V
Common 3.3 V converted from the 5 V line
by the 3.3 V regulator circuit (IC1801). The
output voltage is applied to the D/A convert-
er ICs (IC2151–IC5155), etc.
5 V
Common 5 V converted from the H V line by
the 5 V regulator circuit (IC1951). The output
voltage is applied to the CODEC IC (LOGIC
unit; IC551), low-pass filters (LOGIC unit;
IC451, IC502), etc.
8 V
Common 8 V line converted from the HV
line by the 8 V regulator circuit (IC1901).
The output voltage is applied to the buffer
amplifiers (IC2101–IC2103), analog switches
(IC2156, IC2251), etc.
T 8
Transmit 8 V controlled by the T8 regulator
circuit (Q1703, Q1704) using TXS signal
from the CPU (LOGIC unit; IC1302, pin
106). The output voltage is applied to the RF
switch (Q101), 2nd IF amplifier (Q701), 3rd
IF amplifier (Q901), etc.
R 8
Receive 8 V controlled by the R8 regulator
circuit (Q1701, Q1702) using RXS signal
from the CPU (LOGIC unit; IC1302, pin 105).
The output voltage is applied to the 2nd IF
amplifier (Q702), 3rd IF amplifier (Q1001),
3rd mixer (Q1101), etc.
3 - 9
3-6 PORT ALLOCATIONS
3-6-1 SUB-CPU (DISPLAY UNIT; IC2003)
Pin
number
Port
name
Description
3, 5
MDBK,
MDAK
Input ports for [DIAL].
13, 14
S1AK,
S1BK
Input ports for [PBT2/M-ch] control.
15, 16
S2AK,
S2BK
Input ports for [PBT1/RIT] control.
21 VRK Input port for [AF] switch.
22 PBTK Input port for [PBT/M-ch] switch.
23 TUNK Input port for [TUNER/CALL] key.
24 TSK Input port for [TS] key.
25 LCKK Input port for [LOCK] key.
26 BUPK Input port for [
Y
(BAND)] key.
27 BDNK Input port for [
Z
(BAND)] key.
28 FMSL
Input port for the HM-151 connection
detection.
35 PHNK
I n p u t p o r t fo r t h e h e a d p h o n e s
connection detection.
37 LCK
Outputs clock signal for the LCD driv-
er (IC506).
Pin
number
Port
name
Description
38 LDT
Outputs data signal for the LCD driver
(IC506).
39 LDST
Outputs strobe signal for the LCD
driver (IC506).
47 FSQS
Outputs the squelch control signal.
High : Squelch is opened.
48 RXD
Outputs the RX LED control signal.
High :
While receiving or squelch is
opened.
54 BLV
Outputs the dimmer control signal for
the LCD backlights.
55 KLV
Outputs the dimmer control signal for
the key backlights.
56 TXD
Outputs TX LED control signal.
Low : While transmitting.
57 PBT1D
Outputs control signal for [PBT/M-ch/
RIT] indicator.
Low : While the RIT function is ON.
58 PBT2D
Outputs control signal for [PBT/M-ch/
RIT] indicator.
Low : While the PBT function is ON.
70 LRXD
Input port for data signal from the
main CPU (LOGIC unit; IC1302).
71 LTXD
Outputs data signal to the main CPU
(LOGIC unit; IC1302).
73 AFGL Input port for [AF] control.
74 SQLL Input port for [RF/SQL] control.
75 PTTL
Input port for PTT control signal from
the microphone that is connected to
the FRONT unit.
77 FUDL
Input port for [UP] and [DN] switch-
es from the optional microphone
(HM-103, SM-20) that is connected to
the FRONT [MIC] connector.
78 KI0L
Input port for [MODE], [P.AMP/ATT],
[
Y
(MENU/GRP)] and [
Z
(MENU/
GRP)] keys.
79 KI1L
Input port for [F-1], [F-2], [F-3] and
[F-4] keys.
80 KI2L
Input port for [NB LEV], [NR LEV], [N/
ANF] and [SET/REC] keys.