19
band select pad (BS) selects between GSM and DCS modes of operation. The transmit enable (TX_EN) pad
controls receive or transmit mode of the respective RF switch (TX = logic 1). Proper timing between transmit
enable (TX_EN) and Analog Power Control (VRAMP) allows for high isolation between the antenna and
TXVCO while the VCO is being tuned prior to the transmit burst.
The SKY77518-21 is compatible with logic levels from 1.2 V to VCC for BS and TX_EN pads, depending on
the level applied to the VLOGIC pad. This feature provides additional flexibility for the designer in the selection
of FEM interface control logic.
3.2.2 GB100a/GB105a/GB101a/GB107a (SKY77517)
Figure.3-2-2 SKY77518 FUNCTIONAL BLOCK DIAGRAM
The SKY77517–21 is a transmit and receive front-end module (FEM) with Integrated Power Amplifier Control
(iPAC.) for dual-band cellular handsets comprising GSM850 and PCS1900 operation. Designed in a low profile,
compact form factor, the SKY77517–21 offers a complete Transmit VCO-to-Antenna and Antenna-to-Receive
SAW filter solution. The FEM also supports Class 12 General Packet Radio Service (GPRS) multi-slot
operation.
The module consists of a GSM850 PA block and a PCS1900 PA block, impedance-matching
circuitry for 50 Ω input and output impedances, TX harmonics filtering, high linearity and low insertion loss
PHEMT RF switches, diplexer and a Power Amplifier Control (PAC) block with internal current sense resistor.
A custom BiCMOS integrated circuit provides the internal PAC function and decoder circuitry to control the RF
switches. The two Heterojunction Bipolar Transistor (HBT) PA blocks are fabricated onto a single Gallium
Summary of Contents for GB108
Page 1: ...1 GB108 Service Manual LG Electronics ...
Page 11: ...11 3 TECHNICAL BRIEF Digital Main Processor Figure 3 1 PMB7880 FUNCTIONAL BLOCK DIAGRAM ...
Page 12: ...12 ...
Page 22: ...22 RTC 32 768KHz Crystal Figure 3 4 E GoldVoice RTC Interface ...
Page 24: ...24 ...
Page 25: ...25 3 6 SIM Card Interface Figure 3 6 SIM CARD Interface ...
Page 26: ...26 3 7 KEYPAD Interface Figure 3 7 KEY MAXTRIX Interface ...
Page 27: ...27 3 8 Battery Charging Block Interface Figure 3 8 Charging IC Interface ...
Page 28: ...28 3 9 RF Interface Figure 3 9 RF Module SAW Filter Interface ...
Page 29: ...29 ...
Page 30: ...30 3 10 Audio Interface Figure 3 10 1 Audio Interface ...
Page 31: ...31 ...
Page 32: ...32 Figure 3 10 2 Main Speaker Receiver Interface ...
Page 33: ...33 Figure 3 10 3 Main Microphone Interface Figure 3 10 4 Headset Interface ...
Page 36: ...36 3 13 Memory Interface Figure 3 13 Memory Interface ...
Page 39: ...39 3 15 FM Radio Interface GB105a b GB106 GB107a b GB108 only Figure 3 15 FM Radio Interface ...
Page 41: ...41 ...
Page 42: ...42 PAM Matching component Mobile SW Antenna Matching component Antenna connect point ...
Page 43: ...43 ...
Page 44: ...44 ...
Page 45: ...45 ...
Page 46: ...46 ...
Page 47: ...47 ...
Page 48: ...48 TP2 TP1 TP3 ...
Page 49: ...49 TP2 TP1 TP3 ...
Page 50: ...50 ...
Page 52: ...52 Circuit Diagram TP5 TP6 TP1 TP3 TP4 TP2 ...
Page 54: ...54 4 4 SIM Card Trouble Test Point Circuit Diagram ...
Page 56: ...56 4 5 Vibrator Trouble Test Point Circuit Diagram ...
Page 58: ...58 4 6 Keypad Trouble Test Point Circuit Diagram ...
Page 59: ...59 Checking Flow Change Metal Dome Check Metal Dome Start Change PCB NG OK ...
Page 60: ...60 4 7 RTC Trouble Test Point Circuit Diagram ...
Page 62: ...62 4 8 Key Backlight Trouble Test Point ...
Page 63: ...63 Circuit Diagram ...
Page 65: ...65 4 9 LCM Backlight Trouble Test Point Circuit Diagram ...
Page 67: ...67 4 10 LCM Trouble Test Point Circuit Diagram ...
Page 69: ...69 4 11 Microphone Trouble Test Point Circuit Diagram ...
Page 71: ...71 4 12 Receiver Trouble Test Point Circuit Diagram ...
Page 73: ...73 4 13 Speaker Trouble Test Point Circuit Diagram TP6 TP5 TP2 TP3 TP4 TP1 ...
Page 75: ...75 4 14 Headphone Trouble Test Point ...
Page 76: ...76 Circuit Diagram TP1 TP2 ...
Page 79: ...79 4 15 Charging Trouble Test Point Circuit Diagram ...
Page 81: ...81 4 16 FM Radio Trouble GB105a b GB106 GB107a b only Test Point ...
Page 82: ...82 Circuit Diagram ...
Page 86: ...86 5 DOWNLOAD 5 1 Download Setup ...
Page 91: ...91 6 BLOCK DIAGRAM ...
Page 92: ...92 ...
Page 93: ...93 ...
Page 94: ...94 ...
Page 95: ...95 ...
Page 96: ...96 ...
Page 97: ...97 ...
Page 99: ...99 BGA PIN Check of Memory Top View Use U201 Memory S71GL032N40BFW0P Not Use EUSY0328002 ...
Page 100: ...100 9 PCB LAYOUT ...
Page 105: ...105 11 Calibration 11 1 Test equipment setup 11 2 Calibration Steps Execute HK_36 exe ...
Page 107: ...107 Select MODEL Click START for RF calibration RF Calibration finish ...
Page 113: ...113 13 EXPLODED VIEW REPLACEMENT PART LIST 13 1 Exploded View GB108 ...
Page 114: ...114 ...