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/EDGE and UMTS band
upconverters and downconverters; with the help of these LO generation and distribution circuits, true
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 (U104: AWT6277R)
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 specification.
3. TECHNICAL BRIEF
- 25 -
[Figure 1.5] WCDMA PAM, Duplexer, Coupler
8 dB
Rev. 1.0
Rev.I
20dB
C175
22u
51
R122
NA
C179
FL104
ANT
2
1
GND1
GND2
4
8
GND3
GND4
9
GND5
6
GND6
3
7
RX
5
TX
SAYZY1G95EB0B00
L122
6.8nH
EFCH1950TDF1
FL103
G1
2
G2
3
G3
5
IN
1
O1
4
12p
C174
C180
NA
L125
NA
120
R124
KRX102E
2
4
5
3
1
Q100
SCDY0003402
50OHM
4
3
COUP
2
IN
1
OUT
U103
100p
C186
C177
100p
C184
1.8nH
100p
C183
R125
120
C181
1.5nH
C176
0.01u
L121
8.2p
0.01u
C178
3
GND2
6
7
GND3
9
GND4
GND5
11
2
RFIN
RFOUT
8
VCC1
1
10
VCC2
4
VMODE
VREF
5
AWT6277R
U104
GND1
27p
L124
C185
0.75p
33p
C182
R123
51
L123
8.2nH
+VPWR
WCDMA_2100_TX_OUT
RX_WCDMA_2100
PA_R1
PWR_DET
PA_ON
VREG_TCXO_2.85V
Summary of Contents for U970
Page 1: ...Date April 2007 Issue 1 0 Service Manual Model U970 KU970 Service Manual U970 KU970 ...
Page 3: ... 4 ...
Page 20: ...3 TECHNICAL BRIEF 21 Fig 1 2 RTR6275 RX feature ...
Page 28: ...3 TECHNICAL BRIEF 29 Figure1 7 PM6650 Block Diagram ...
Page 41: ...3 TECHNICAL BRIEF 42 Table 1 1 Summary of MSM6280 device features ...
Page 45: ...3 TECHNICAL BRIEF 46 Figure 1 1 PM6650 Functional Block Diagram ...
Page 76: ...4 TROUBLE SHOOTING 77 4 1 RF CRF Component TOP SIDE BOTTOM SIDE 4 TROUBLE SHOOTING ...
Page 81: ...4 TROUBLE SHOOTING 82 Check C412 of PMIC U400 Check R214 of MSM U200 ...
Page 83: ...4 TROUBLE SHOOTING 84 Logic Table of the FEM ...
Page 89: ...4 TROUBLE SHOOTING 90 4 7 Checking GSM Block ...
Page 91: ...4 7 3 Checking RF Tx level 4 TROUBLE SHOOTING 92 ...
Page 94: ...4 TROUBLE SHOOTING 95 ...
Page 100: ...4 TROUBLE SHOOTING 101 R403 Q402 Q401 Q400 Charging part Main PCB Front ...
Page 103: ...4 TROUBLE SHOOTING 104 Q400 X 200 USB part 1 Main PCB Front U503 USB part 2 Main PCB Rear ...
Page 112: ...4 TROUBLE SHOOTING 113 CN601 CN701 CN700 ...
Page 115: ...4 TROUBLE SHOOTING 116 C500 C501 R501 R502 ...
Page 117: ...4 TROUBLE SHOOTING 118 SPK Audio Amplifier Analog Switch ...
Page 119: ...4 TROUBLE SHOOTING 120 MIC800 R507 C520 ...
Page 121: ...4 TROUBLE SHOOTING 122 R303 Ear_Sense_N C210 MIC Input ...
Page 141: ...5 DOWNLOAD 142 ...
Page 147: ...5 DOWNLOAD 148 Read IMEI BT address from UE 2 Step 4 Check IMEI and Bluetooth address ...
Page 158: ...6 BLOCK DIAGRAM 159 Table 2 1 RF Block Component ...
Page 163: ...6 BLOCK DIAGRAM 164 6 2 4 Placement Top Side ...
Page 164: ...6 BLOCK DIAGRAM 165 Bottom Side ...
Page 165: ... 166 ...
Page 175: ... 176 8 PCB LAYOUT U970 KU970 ...
Page 176: ... 177 8 PCB LAYOUT U970 KU970 ...
Page 177: ... 178 8 PCB LAYOUT U970 KU970 ...
Page 178: ... 179 8 PCB LAYOUT U970 KU970 ...
Page 179: ... 180 8 PCB LAYOUT ...
Page 180: ... 181 8 PCB LAYOUT ...
Page 181: ... 182 ...
Page 187: ... 188 ...
Page 189: ... 190 ...
Page 209: ...Note ...
Page 210: ...Note ...