
4.6.1 Checking VCO Block
4. TROUBLE SHOOTING
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TP4
TP5
TP6
TP1
TP2
TP3
925-960 MHz
(PPS)
43
VDD_M
TX_VCO_FB
42
39
VDDA11
VDDA12
41
VDDA13
48
47
RF_ON_TX_ON
SBCK
44
SBDT
45
46
SBST
40
TX_MOD_CP
38
R1026
100
1000p
C1085
C1067
R1035
270
0.1u
R1036
47
15p
9.1nH
L1015
C1068
51
R1034
R1030
51
R1032
15
C1084
22n
C1073
10u
82
R1037
FB1000
33p
C1065
C1081
0.01u
10nH
L1028
0.1u
C1076
C1077
0.1u
120p
C1083
100
R1025
C1086
1000p
C1079
82p
R1033
220
C1072
22p
R1027
24
R1028
150
C1069
10u
2
GND1
4
GND2
6
GND3
GND4
7
8
GND5
12
GND6
GND7
13
14
GND8
OUT_DCSPCS
5
OUT_GSM
1
SW1
9
SW2
11
VB
3
10
VC
MQW5V0C869M
U1003
R1029
200
15p
C1066
C1080
100p
VREG_RFTX_2.85V
VREG_MSMP_2.7V
GSM_TX_VCO_0_EN_N
GSM_TX_VCO_1_EN_N
VREG_RFTX_2.85V
SBCK
SBDT
SBST
Test Point (TXVCO Level)
Schematic of RF TXVCO
TP5
TP6
TP1
TP4
TP2
TP3
Summary of Contents for U880
Page 1: ...Date November 2005 Issue 1 0 Service Manual Model U880 Service Manual U880 ...
Page 20: ...3 TECHNICAL BRIEF 21 ...
Page 32: ...3 TECHNICAL BRIEF 33 Figure 3 5 6 1 GSM PA functional block diagram ...
Page 35: ...3 TECHNICAL BRIEF 36 Figure 3 5 10 1 Bluetooth system architecture ...
Page 50: ...3 TECHNICAL BRIEF 51 Figure 3 10 3 2 1 PM6650 Functional Block Diagram ...
Page 114: ...4 TROUBLE SHOOTING 115 Loud Speaker U502 U503 Amp ...
Page 118: ...4 TROUBLE SHOOTING 119 C200 C201 for MIC serial capacitor ...
Page 121: ...4 TROUBLE SHOOTING 122 Q404 Q403 Q402 VBATT GND ...
Page 128: ...5 DOWNLOAD 129 5 Choose a Module Image file after clicking on the Browse button ...
Page 143: ...6 BLOCK DIAGRAM 144 6 3 Interface Diagram U880 Interface Diagram ...
Page 145: ... 146 ...
Page 154: ... 155 8 PCB LAYOUT ...
Page 155: ... 156 8 PCB LAYOUT ...
Page 156: ... 157 8 PCB LAYOUT ...
Page 157: ... 158 8 PCB LAYOUT ...
Page 158: ... 159 8 PCB LAYOUT ...
Page 159: ... 160 8 PCB LAYOUT ...
Page 166: ...9 CALIBRATION 167 Click START button U880 U880_ver1 1 U880 U880 Click U880 ...
Page 167: ... 168 ...
Page 168: ... 169 ...
Page 170: ... 171 ...
Page 171: ... 172 ...
Page 196: ...Note ...
Page 197: ...Note ...