3.2.2 GSM Transmitter
The RTR6275 transmitter outputs(DA_HB2_OUT and DA_LB1_OUT)include on-chip output matching
inductors. 50ohm output impedance is achieved by adding a series capacitor at the output pins. The
capacitor value may be optimized for specific applictions and PCB characteristics based on pass-band
symmetry about the band center frequency, the suggested starting value is shown in Figure1.2.
The RTR6275 IC is able to support GSM 900 and GSM 1800/1900 mode transmitting. This design
guideline shows a tri-band GSM application.
Both high-band and low band outputs are followed by resistive pads to ensure that the load Presented
to the outputs remains close to 50ohm. The low-band GSM. Tx path also includes a Tx-band SAW filter
to remove noise-spurious components and noise that would be amplified by the PA and appear in the
GSM Rx band
3. TECHNICAL BRIEF
- 22 -
91
Ω
91
Ω
6pF
120
Ω
120
Ω
68
Ω
5pF
51
Ω
[Fig 1.3] GSM Transmitter matching
Содержание U970
Страница 1: ...Date April 2007 Issue 1 0 Service Manual Model U970 KU970 Service Manual U970 KU970 ...
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 1 Summary of MSM6280 device features ...
Страница 45: ...3 TECHNICAL BRIEF 46 Figure 1 1 PM6650 Functional Block Diagram ...
Страница 76: ...4 TROUBLE SHOOTING 77 4 1 RF CRF Component TOP SIDE BOTTOM SIDE 4 TROUBLE SHOOTING ...
Страница 81: ...4 TROUBLE SHOOTING 82 Check C412 of PMIC U400 Check R214 of MSM U200 ...
Страница 83: ...4 TROUBLE SHOOTING 84 Logic Table of the FEM ...
Страница 89: ...4 TROUBLE SHOOTING 90 4 7 Checking GSM Block ...
Страница 91: ...4 7 3 Checking RF Tx level 4 TROUBLE SHOOTING 92 ...
Страница 94: ...4 TROUBLE SHOOTING 95 ...
Страница 100: ...4 TROUBLE SHOOTING 101 R403 Q402 Q401 Q400 Charging part Main PCB Front ...
Страница 103: ...4 TROUBLE SHOOTING 104 Q400 X 200 USB part 1 Main PCB Front U503 USB part 2 Main PCB Rear ...
Страница 112: ...4 TROUBLE SHOOTING 113 CN601 CN701 CN700 ...
Страница 115: ...4 TROUBLE SHOOTING 116 C500 C501 R501 R502 ...
Страница 117: ...4 TROUBLE SHOOTING 118 SPK Audio Amplifier Analog Switch ...
Страница 119: ...4 TROUBLE SHOOTING 120 MIC800 R507 C520 ...
Страница 121: ...4 TROUBLE SHOOTING 122 R303 Ear_Sense_N C210 MIC Input ...
Страница 141: ...5 DOWNLOAD 142 ...
Страница 147: ...5 DOWNLOAD 148 Read IMEI BT address from UE 2 Step 4 Check IMEI and Bluetooth address ...
Страница 158: ...6 BLOCK DIAGRAM 159 Table 2 1 RF Block Component ...
Страница 163: ...6 BLOCK DIAGRAM 164 6 2 4 Placement Top Side ...
Страница 164: ...6 BLOCK DIAGRAM 165 Bottom Side ...
Страница 165: ... 166 ...
Страница 175: ... 176 8 PCB LAYOUT U970 KU970 ...
Страница 176: ... 177 8 PCB LAYOUT U970 KU970 ...
Страница 177: ... 178 8 PCB LAYOUT U970 KU970 ...
Страница 178: ... 179 8 PCB LAYOUT U970 KU970 ...
Страница 179: ... 180 8 PCB LAYOUT ...
Страница 180: ... 181 8 PCB LAYOUT ...
Страница 181: ... 182 ...
Страница 187: ... 188 ...
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Страница 209: ...Note ...
Страница 210: ...Note ...