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3.5.2 VCTCXO (X100 : DSA321SCE-19.2M)
The Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO) provides the
reference frequency for all RFIC synthesizers as well as clock generation functions within the
MSM6245 IC. The oscillator frequency is controlled by the MSM6245 IC.
TRK_LO_ADJ pulse density modulated signal in the same manner as the transmit gain control
TX_AGC_ADJ. A two-pole RC lowpass filter is recommended on this control line.
The PM6650 IC controls the handset power-up sequence, including a special VCTCXO warm-up
interval before other circuits are turned on. This warm-up interval (as well as other TCXO controller
functions) is enabled by the MSM TCXO_EN line . The PM6650 IC VREG_TCXO regulated output
voltage is used to power the VCTCXO and is enabled before most other regulated outputs.
Any GSM mode power control circuits within the MSM6245 IC require a reference voltage for proper
operation and sufficient accuracy. Connecting the PM6650 IC REF_OUT directly to the MSM6245 IC
GSM_PA_PWR_CTL_REF provides this reference. This sensitive analog signal needs a 0.1 •ÏF low
frequency filter near to MSM side, and isolate from digital logic and clock traces with ground on both
sides, plus ground above and below if routed on internal layers.
3.5.3 Front-End Module (U500 : D5011)
This equipment uses a single antenna to support all handset operating modes, with an antenna switch
module select the operating frequency and band. UMTS operation requires simultaneous reception
and transmission, so the UMTS Rx/Tx connection is routed to a duplexer that separates receive and
transmit signals. The active connection is MSM-selected by three control lines (GPIO[9], GPIO[10]).
Two GPIO are programmed to be ANT_SEL0_N, ANT_SEL1_N) respectively.
3. TECHNICAL BRIEF
- 26 -
GSM 1800 / GSM1900 RX
GSM 900 RX
GSM 900 TX / WCDMA
GSM 1800 / GSM 1900 TX
[Table 1.2] Front End Module control logic
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 ...