Icom IC-M803 Service Manual page 81

• DC-DC UNIT
R9673
IC9671
1
CTRL
2
GND
3
NC
NJM2831F05
R9671
DCLK_P
100 SN74LVC1GU04DCKR
1
2
3
IC9672
R9701
DCLK_P
SN74LVC1GU04DCKR
100
1 5
2
3 4
IC9701
EP9701
14V
MPZ2012S601A
C9723
R9722
DCLK_N
100
MPZ2012S601A
EP9721
14V
10K
5
VIN
4
VOUT
H4V
C9676
0.1
5
4
L9701
3.3U
C9704
0.1
8V
0.1
13.4
14V
14V
HV
HV
MPZ2012S601A
L9671
EP9671
H4V
3.3U
MP9671 3183
H4V
I5V
R9705
3.90K
R9706
3.90K
IC9751
NJM7805DL1A
MPZ2012S601A
EP9722
R9751
I
5.6
G
R9752
5.6
A5V
8V
8
Explanatory notes
TX Line
RX Line
Voltage Line
11-15
13.4
IC9691
CE VOFB
5 4
VSS ILIM
6 3
NC NC
7 2
VIN VOUT
8 1
XC6230H001QR
H3R3V
4 3.3
I5V
EP9781
MPZ2012S601A
EP9788
4.9
MPZ2012S101A
EP9782
MPZ2012S101A
5.1
EP9783
EP9787 MPZ1608S601A
MPZ2012S101A
A5V
EP9785
O
MPZ1608S601A
8V EP9884
MPZ1608S601A
DCLK_P
DCLK_N
Measuring condition:
• Frequency: 12.23 MHz
• Mode: J3E (USB)
• RX: No signal is received.
• TX: No modulation signal is applied.
(Waveforms are measured by an Oscilloscope.)
Digital tester setting:
Measuring Range
200 mV
2 V
20/200/1000 V
Voltage notation:
TX
RX
RX
TO MAIN
J9781
1 HV
2 HV
3
HV
4 14V
5 14V
6 14V
7 14V
8 14V
9 NC
10 H3R3V
11 H3R3V
12 H3R3V
13 H4V
14 I5V
15 I5V
16 I5V
17 I5V
18
A5V
19 8V
20 8V
21 NC
22 GND
23 GND
24 GND
25 GND
26 GND
27 GND
28 GND
29 DCKL_P
DCKL_N
30
(unless otherwise noted)
Input impedance
100 M
11 M
10 M
Unit: Volt