3.5.9 VCTCXO (X100)
The Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO) provides the
reference frequency for all RFIC synthesizers as well as clock generation functions within the
MSM6250A IC. The 6250-series chipset requires a 19.2 MHz nominal VCTCXO frequency. The
oscillator frequency is controlled by the MSM6250A’s TRK_LO_ADJ pulse density modulated signal in
the same manner as the transmit gain control.
The filtered PDM signal results in an analog control signal into the VCTCXO tuning port whose voltage
is directly proportional to the density of the digital bit stream. The MSM device varies the pulse density
to change the analog control voltage that sets the oscillator frequency - all within a feedback control
loop that minimizes handset frequency drift relative to the network.
3.5.10 Bluetooth (U502 : LBDA254AN0,TP500 : ALA931C5F1 )
The MSM6250A includes BT baseband embedded BT 1.1 compliant baseband core, so the other
bluetooth components are an bluetooth RF module and Antenna. Figure3.5.12-1 shows the bluetooth
system architecture in the U890.
3. TECHNICAL BRIEF
- 34 -
Figure 3.5.10-1 Bluetooth system architecture
Содержание U890
Страница 1: ...Date April 2006 Issue 1 0 Service Manual Model U890 U890c Service Manual U890 U890c ...
Страница 3: ... 4 ...
Страница 20: ...3 TECHNICAL BRIEF 21 ...
Страница 46: ...3 TECHNICAL BRIEF 47 Figure PM6650 2 Functional Block Diagram ...
Страница 70: ...4 TROUBLE SHOOTING 71 4 2 SIGNAL PATH ...
Страница 109: ...4 TROUBLE SHOOTING 110 CN600 50pin LCD connector CN901 C907 C911 FB901 FB902 ...
Страница 115: ...4 TROUBLE SHOOTING 116 C226 C227 for MIC serial capacitor ...
Страница 118: ...4 TROUBLE SHOOTING 119 Q400 Q401 Q402 VBATT GND ...
Страница 139: ...Table 2 1 1 RF Block Component 6 BLOCK DIAGRAM 140 ...
Страница 140: ...6 BLOCK DIAGRAM 141 6 2 Interface Diagram U890 Interface Diagram ...
Страница 142: ...6 BLOCK DIAGRAM 143 Top Side ...
Страница 143: ...6 BLOCK DIAGRAM 144 Bottom Side ...
Страница 152: ... 153 8 pcb layout ...
Страница 153: ... 154 8 pcb layout ...
Страница 154: ... 155 8 pcb layout ...
Страница 155: ... 156 8 pcb layout ...
Страница 156: ... 157 8 pcb layout ...
Страница 157: ... 158 8 pcb layout ...
Страница 163: ...9 CALIBRATION 164 9 3 HOT KIMCHI Example Choose_U890 ...
Страница 164: ...9 CALIBRATION 165 Click APPLY button Click START button ...
Страница 165: ...9 CALIBRATION 166 Click Run button to lunch RF AUTOTEST ...
Страница 167: ... 168 ...
Страница 191: ...Note ...
Страница 192: ...Note ...