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3.4 LO generation and distribution circuits
The integrated LO generation and distribution circuits are driven by internal VCOs to support various
modes to yield highly flexible quadrature LO outputs that drive all GSM and UMTS band upconverters
and downconverters; with the help of these LO generation and distribution circuits, zero-IF architecture
is employed in all GSM and UMTS band receivers and transmitters to translate the signal directly from
RF to baseband and from baseband to RF.
Two fully functional fractional-N synthesizers, including VCOs and loop filters, are integrated within the
RTR6275 IC. The first synthesizer (PLL1) creates the transceiver LOs that support the UMTS
2100/1900/1800 transmitter, and all four GSM band receivers and transmitters including: GSM 850,
GSM 900, GSM 1800, and GSM 1900. The second synthesizer (PLL2) provides the LO for the UMTS
2100/1900/1800 receiver. An external TCXO input signal is required to provide the synthesizer
frequency reference to which the PLL is phase and frequency locked. The RTR6275 IC integrates
most of PLL loop filter components on-chip except two off-chip loop filter series capacitors, and
significantly reduces off-chip component requirement. With the integrated fractional-N PLL
synthesizers, the RTR6275 has the advantages of more flexible loop bandwidth control, fast lock time,
and low-integrated phase error
3.5 Off-chip RF Components
3.5.1 WCDMA PAM (U103: WS2512-TR1G)
The UMTS PA output power is monitored by l power detector circuits(U100 : RTR6275) .
This detector voltage can be used for transmitter calibration and monitor to meet RF system
3. TECHNICAL BRIEF
- 25 -
[Figure 1.5] WCDMA PAM, Duplexer, Coupler
20dB
Rev_1.0
Rev.B
Rev_1.0
Rev.D
WCDMA
7dB
0.5p
L125
FL102
EFCH1950TDF1
2
G1
3
G2
5
G3
1
IN
4
O1
U102
CP0402A1950DNTR
50OHM
4
3
COUP
2
IN
1
OUT
L404
1.8nH
45
31
NA
L122
KRX102U
TR100
2
1p
C165
3.3p
C162
C159
15p
R122
130
R119
51
1.5p
C154
4
1
RX
TX
2
FL104
ACMD-7602
ANT
3
PGND
130
R121
0.1u
C170
4.7u
C155
47
R120
2
RFOUT
8
1
VCC1
VCC2
10
4
VCONT
5
VREF
WS2512_TR1G
U103
11
BGND
GND1
3
GND2
6
7
GND3
9
GND4
RFIN
0.5p
C164
100p
C192
C158
15p
1nH
L123
10nH
C157
+VPWR
PA_R0
+VPWR
PWR_DET
PA_ON
VREG_TCXO_2.85V
Содержание U250
Страница 1: ...Date June 2007 Issue 1 0 Service Manual Model U250 KU250 Service Manual U250 KU250 ...
Страница 3: ... 4 ...
Страница 20: ...3 TECHNICAL BRIEF 21 Fig 1 2 RTR6275 RX feature ...
Страница 23: ...3 TECHNICAL BRIEF 24 Figure 1 4 RTR6275 IC functional block diagram WCDMA_2100_TX WCDMA_2100_RX ...
Страница 28: ...3 TECHNICAL BRIEF 29 Figure1 7 PM6650 Block Diagram ...
Страница 41: ...3 TECHNICAL BRIEF 42 Table 1 2 Description of RF configurations ...
Страница 45: ...3 TECHNICAL BRIEF 46 Figure 1 12 PM6650 Functional Block Diagram ...
Страница 72: ...4 TROUBLE SHOOTING 73 4 1 RF Component 4 TROUBLE SHOOTING LGMC ...
Страница 73: ...4 TROUBLE SHOOTING 74 Block Diagram Block Ref Name UMTS Part Name Function Comment ...
Страница 77: ...4 TROUBLE SHOOTING 78 Check C312 of PMIC U300 Check R213 of MSM U201 T ...
Страница 81: ...4 TROUBLE SHOOTING 82 ...
Страница 84: ...4 TROUBLE SHOOTING 85 ...
Страница 85: ...4 TROUBLE SHOOTING 86 4 7 Checking GSM Block 1 3 2 ...
Страница 87: ...4 7 3 Checking RF Tx level 4 TROUBLE SHOOTING 88 ...
Страница 90: ...4 TROUBLE SHOOTING 91 ...
Страница 97: ...4 TROUBLE SHOOTING 98 R313 Q301 Q302 Q300 Charging part Main PCB Front ...
Страница 107: ...4 TROUBLE SHOOTING 108 R422 R421 U401 ...
Страница 109: ...4 TROUBLE SHOOTING 110 C401 C402 R406 C407 CN401 ...
Страница 111: ...4 TROUBLE SHOOTING 112 Analog Switch Audio Amp SPK ...
Страница 113: ...4 TROUBLE SHOOTING 114 MIC400 C417 R424 ...
Страница 115: ...4 TROUBLE SHOOTING 116 Ear_Sense_N MIC Input ...
Страница 117: ...4 TROUBLE SHOOTING 118 VPWR MOTOR_PWR ...
Страница 133: ...6 BLOCK DIAGRAM 134 6 1 GSM UMTS RF Block 6 BLOCK DIAGRAM Fig 2 1 U250 KU250 RF Functional Block Diagram ...
Страница 134: ...6 BLOCK DIAGRAM 135 Table 2 1 RF Block Component ...
Страница 136: ...6 BLOCK DIAGRAM 137 6 2 2 Memory Interface Fig 2 3 Memory Interface Diagram ADDRESS 14 0 ...
Страница 137: ...6 BLOCK DIAGRAM 138 6 2 3 USB UART SIM JTAG Interface Fig 2 4 USB UART SIM JTAG Interface ...
Страница 139: ...6 BLOCK DIAGRAM 140 6 2 4 Placement Top Side LGMC ...
Страница 140: ...6 BLOCK DIAGRAM 141 Bottom Side LGMC ...
Страница 141: ... 142 ...
Страница 146: ... 147 LGMC 8 PCB LAYOUT U250 KU250 ...
Страница 147: ... 148 LGMC 8 PCB LAYOUT U250 KU250 ...
Страница 157: ... 158 ...
Страница 174: ...Note ...
Страница 175: ...Note ...