40
3.15.1 FM Tuner (GB105a/b&GB106&GB107a/b&GB108 only)
The Si4702 patented digital low-IF architecture reduces external components and eliminates the
need for factory adjustments. The receive (RX) section integrates a low noise amplifier (LNA)
supporting the worldwide FM broadcast band (76 to 108 MHz). Anautomatic gain control (AGC)
circuit controls the gain of the LNA to optimize sensitivity and rejection of strong interferers.
For two-wire operation, a transfer begins with the START condition. The control word is latched
internally on rising SCLK edges and is eight bits in length, comprised of a seven bit device
address equal to 0010000b and a read/write bit (write = 0 and read = 1). The device
acknowledges the address by setting SDIO low on the next falling SCLK edge. For write
operations, the device acknowledge is followed by an eight bit data word latched internally on
rising edges of SCLK. The device always acknowledges the data by setting SDIO low on the next
falling SCLK edge. An internal address counter automatically increments to allow continuous data
byte writes, starting with the upper byte of register 02h, followed by the lower byte of register 02h,
and onward until the lower byte of the last register is reached. The internal address counter then
automatically wraps around to the upper byte of register 00h and proceeds from there until
continuous writes cease. Data transfer ceases with the STOP command. After every STOP
command, the internal address counter is reset. For read operations, the device acknowledge is
followed by an eight bit data word shifted out on falling SCLK edges. An internal address counter
automatically increments to allow continuous data byte reads, starting with the upper byte of
register 0Ah, followed by the lower byte of register 0Ah, and onward until the lower byte of the last
register is reached. The internal address counter then automatically wraps around to the upper
byte of register 00h and proceeds from there until continuous reads cease. After each byte of
data is read, the controller IC should return an acknowledge if an additional byte of data will be
requested. Data transfer ceases with the STOP command. After every STOP command, the
internal address counter is reset.
3.15.2 Headphone Amplifier
The TS486 is a dual audio power amplifier capable of driving, in single-ended mode, either a 16
or a 32W stereo headset. Capable of descending to low voltages, it delivers up to 90mW per
channel (into 16W loads) of continuous average power with 0.3% THD+N in the audio bandwitdth
from a 5V power supply. An externally-controlled standby mode reduces the supply current to
10nA (typ.). The unity gain stable TS486 can be configured by external gain-setting resistors or
used in a fixed gain version.
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 ...
