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3. TECHNICAL BRIEF
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A. TX IF Modulator
The TX I and Q signals from BB analog chipset, AD6521(U2), #F9, E9, C9, D9 are fed to #17~20 of
the HD155128TF TX modulator(U301), where they are then modulated onto either a TX IF of
270MHz(for GSM-TX) or 135MHz(for DCS-TX) by the quadrature mixer inside U301. The signal TX
LO IF(270MHz,135MHz) is input from U301. This signal is produced by the external 1,080 MHz IF
VCO of synthesizer Si4133G_XM2(U302), which has been divided down by a factor of 4 for GSM-
TX or 8 for DCS-TX. This division factor is set by the control signal of BB digital chipset,
AD6522(U3) #D14, D13, F11.
The modulator provides more than 40 dBc of carrier and unwanted side-band rejection and
produces a GMSK modulated signal. The BB software is able to cancel out differential DC offsets in
the I/Q BB signals caused by imperfections in the D/A converters. The TX-Modulator implements a
quadrature modulator. The IF-frequency input signal is split into two precise orthogonal carriers,
which are multiplied by the BB modulation signal IT/ITX and QT/QTX. It is used as reference signal
for the OPLL.
Figure 3-6. TX IF Modulator and OPLL Circuit.
Содержание LG-510W
Страница 1: ...GSM Phone SERVICE MANUAL MODEL LG 510W SERVICE MANUAL MODEL 510W ...
Страница 27: ...3 TECHNICAL BRIEF 26 3 8 Power Management ADP3408 Figure 3 12 ADP3408 Inner Block Diagram ...
Страница 30: ...3 TECHNICAL BRIEF 29 Figure 3 13 Keypad Switches and Scanning ...
Страница 34: ...4 TROUBLE SHOOTING 33 4 TROUBLE SHOOTING Fig 4 1 shows a measurement set up Figure 4 1 Measurement Set up ...
Страница 35: ...4 1 RX Trouble 4 TROUBLE SHOOTING 34 ...
Страница 36: ...4 TROUBLE SHOOTING 35 RX Level Check EGSM ...
Страница 37: ...4 TROUBLE SHOOTING 36 RX Level Check DCS ...
Страница 38: ...4 2 TX Trouble 4 TROUBLE SHOOTING 37 ...
Страница 39: ...4 TROUBLE SHOOTING 38 TX Level Check ...
Страница 41: ...4 TROUBLE SHOOTING 40 4 3 Power on Trouble ...
Страница 42: ...4 TROUBLE SHOOTING 41 ...
Страница 43: ...4 TROUBLE SHOOTING 42 4 4 Charge Trouble ...
Страница 44: ...4 TROUBLE SHOOTING 43 4 5 LCD Trouble ...
Страница 45: ...4 TROUBLE SHOOTING 44 4 6 Receiver Trouble ...
Страница 46: ...4 TROUBLE SHOOTING 45 4 7 Buzzer Trouble ...
Страница 47: ...4 TROUBLE SHOOTING 46 4 8 MIC Trouble ...
Страница 48: ...4 TROUBLE SHOOTING 47 4 9 Vibrator Trouble ...
Страница 49: ...4 TROUBLE SHOOTING 48 4 10 Indicator LED Trouble ...
Страница 50: ...4 TROUBLE SHOOTING 49 ...
Страница 51: ...4 TROUBLE SHOOTING 50 4 11 Backlight LED Trouble ...
Страница 52: ...4 12 Folder on off Trouble 4 TROUBLE SHOOTING 51 ...
Страница 53: ...4 13 SIM Detect Trouble 4 TROUBLE SHOOTING 52 ...
Страница 54: ...4 14 Earphone Trouble 4 TROUBLE SHOOTING 53 ...
Страница 55: ...4 TROUBLE SHOOTING 54 ...
Страница 56: ...4 TROUBLE SHOOTING 55 4 15 HFK Trouble ...
Страница 57: ...4 TROUBLE SHOOTING 56 ...
Страница 61: ... RF Components Keypad Side Figure 5 2 RF Components Keypad Side 5 TEST POINT DATA 60 U304 APCIC ...
Страница 63: ...5 TEST POINT DATA 62 Figure 5 4 Receiver RF Levels GSM CH 62 60dBm DCS CH 699 60dBm ...
Страница 65: ... Test Point of TX Levels 2 Figure 5 6 Test Point of TX Levels 2 5 TEST POINT DATA 64 10 19 ...
Страница 66: ...5 TEST POINT DATA 65 GSM Pwr LvI 5 CH 62 32dBm DCS Pwr LvI 0 CH 699 29dBm Figure 5 7 Transmitter RF Levels ...
Страница 68: ...5 TEST POINT DATA 67 Control Signal Test Points 2 Figure 5 9 Control Signal Test Points 2 TXEN TXRAMP ...
Страница 69: ...Figure 5 10 Regulator Output RF2V8 Figure 5 11 VCTCXO Power Supply 2V7_VCTCXO 5 TEST POINT DATA 68 ...
Страница 70: ...5 TEST POINT DATA 69 Figure 5 12 13MHz Clock Figure 5 13 Control Signal of FEM in RX mode GSM DCS both ...
Страница 72: ...5 TEST POINT DATA 71 Figure 5 16 CLK DATA SEN Figure 5 17 CLK DATA AGCEN ...
Страница 73: ...Figure 5 18 RXON1 RXON2 Figure 5 19 TXEN TARAMP TXPA 5 TEST POINT DATA 72 ...
Страница 74: ...5 TEST POINT DATA 73 Figure 5 20 TX IQ Signal Figure 5 21 RX IQ Signal ...
Страница 87: ...9 2 FPCB Figure 9 2 FPCB Blockdiagram 9 BLOCK DIAGRAM 86 ...
Страница 88: ...9 BLOCK DIAGRAM 87 9 3 RF Figure 9 3 RF Blockdiagram ...
Страница 89: ...9 BLOCK DIAGRAM 88 ...
Страница 90: ... 89 10 CIRCUIT DIAGRAM 10 CIRCUIT DIAGRAM 10 1 BB Circuit ...
Страница 91: ... 90 10 CIRCUIT DIAGRAM 10 2 RF Circuit ...
Страница 92: ... 91 11 PCB LAYOUT 11 PCB LAYOUT ...
Страница 93: ... 92 11 PCB LAYOUT ...
Страница 95: ...12 DOWNLOAD AND CALIBRATION 94 Figure 12 2 Download Setup Type2 Using JIG ...
Страница 110: ...P N MMBD0012501 DECEMBER 2001 SERVICE MANUAL MODEL 510W ...