Icom IC-M803 Service Manual page 80

• CONNECT UNIT
J7701
R7701
C7720
1
47P
3.3
[GPS ANT]
IC7702
NC ON/OFF
4
VSS
VOUT VIN
5
S-1313D33
MP7701
2590
D7711
L1SS400
J7711
5
AF-
9 GND
4
AF+
8
NSEND
3 GND
7
2
MOD-
6
GND
1 MOD+
[AF/MOD]
47K
R7721
Q7721
L2SC4081
J7721
5
GND
9
4
DTR
R7725
8
CTS
0
3
TXD
R7726
7 RTS
2 0
RXD
R7727
6
DSR
1 DCD
0
R7728
0
[REMOTE]
NMEA selected
RS-232C selected
R7736
270
Q7731
[GPS DATA]
2SC4213
J7751
R7751
Q7751
270
2SC4213
FI7701
TA0757B IC7701
R7702
A1 RF_IN
I O
A2
1 VSS
A3
VSS
A4
VSS
A5 VDD_BKUP_IN
A6
VSS
A7
GPIO0
B1
VSS
B2
VSS
B3
VSS
B4 UART0_RX
5
B5 UART0_CTS
3 B6
VSS
2 B7 UART0_T X
1
C1
VSS
C2
VSS
C3
VSS
C4
NRST
C5 BOOT_MODE0
C6 VDD_IO_HOST
C7
GPIO1
R7711
0
R7712
0
R7723
C7722
Q7722
L2SC4081
10K
0.01
C7726
1
IC7721
C7723
1 16
C1+ VCC
2 15
1
V+ GND
3 14
C1- T1O
C7724 4 13
C2+ R1I
5 12
1
C2- R1O
6 11
C7725
V- T1I
1 7 10
T2O T2I
8 9
R2I R2O
ADM202EARNZ
LDTC143ZE
Q7723
NMEA selected
0
RS-232C selected
13.6 R7738
1
IC7731
LDTC143ZE
Q7792
TLP2303 LDTC143ZE
Q7791
R7755
1
IC7751
TLP2303
D1
VSS
D2
VSS
D3
VSS
D4
NC
D5
VDD_BKUP_BAT_IN
D6
I2C_SCL
D7
I2C_SDA
E1
VSS
E2
VSS
E3
VSS
E4
VSS
E5
VDD_PRPH_OUT
E6
VSS
E7
VSS
GSU-141A
GTX
GRX
GRESL
A5V
A5V
R7713
0
R7714
0
H3R3V
RPC
DTR
L7721 A5V
L7722 100U
10U
IC7722
47K
1 8
R7733
RO VCC
2 7
RE B
3 6
DE A
4 5
DI GND
ADM4853ARZ
EP7891
14V
MPZ2012S601A
NMEA selected 0
RS-232C selected 4.6
R7734
47K
C7730
0.1
IC7723
1 8
2 7
LDTC143ZE
3 6
Q7724
4 5
TC7WH32FU
4.8
0
A5V
IC7791
1 8
2 7
3 6
4 5
TC7W04FU
11-14
EP7701
MPZ2012S101A
5
IC7703
1 5
VIN VOUT
2
VSS
3 ON/OFF 4
NC
S-1313D33
CP7704 CP7703
CP10S CP10S
MPZ2012S101A
14V EP7761
GND
DSEN
DSAFE
GND
GND
GND
GTX_
GRX_
GRESL
GND
H3R3V EP7762 MPZ2012S101A
EP7763 MPZ1608S601A
GND
GND
GND
GND
R7761 220 NMR
R7762 220 RNMEO
R7763 220 RSS
220 DNMEI
R7764
R7765 220 RNMEI
GND
GND
Measuring condition:
(unless otherwise noted)
• Frequency: 12.23 MHz
• Mode: J3E (USB)
• RX: No signal is received.
• TX: No modulation signal is applied.
• Waveforms are measured by
an oscilloscope.
Voltage notation:
TX
RX
RX
TC7W08FU
IC7741
1 8
2 7
3 6
4 5
Explanatory notes
3.3
TO MAIN UNIT
J7761
14V
1
NC
2
GND
3
DSEN
4
DSAF
5
DSAFE
6
DSMD
7
DSMDE
8
GND
9
GND
10
GND
11
GTX
12
GRX
13
GRESL
14
GND
15
H3R3V
16
A5V
17
GND
18
GND
19
GND
20
GND
21
RPC
22
DTR
23
NMR
24
RNMEO
25
RSS
26
DNMEI
27
RNMEI
28
GND
29
GND
30
Unit: Volt
TX Line
RX Line
Voltage Line