LG GU285 User manual

Type
User manual

This manual is also suitable for

Service Manual Model : GU280/GU285
Internal Use Only
Service Manual
GU280/GU285
Date: October, 2009 / Issue 1.0
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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
Table Of Contents
1. INTRODUCTION ...............................................5
1.1 Purpose ......................................................................5
1.2 Regulatory Information .................................................5
2. PERFORMANCE ...............................................7
2.1 Product Name .............................................................7
2.2 Supporting Standard ....................................................7
2.3 Main Parts : Solution ....................................................7
2.4 Feature .......................................................................8
2.5 HW Spec. ..................................................................10
3. Technical Brief .............................................13
3.1. General Description ..................................................13
3.2. WCDMA Part ............................................................14
3.3. EDGE/GPRS/GSM RF block ........................................19
3.5. Control Flow .............................................................24
3.6 General Description ...................................................25
3.7 Power management ..................................................35
4. TROUBLE SHOOTING ..................................... 38
4.1 RF Component ..........................................................38
4.2 RF Path ....................................................................39
4.3 Trouble Shooting of GSM Part (GSM850/900/1800/1900)
......................................................................................40
4.4 Trouble Shooting of WCDMA Part ................................48
4.5 Checking Bluetooth Block ..........................................55
4.6 Checking FM Radio Block ..........................................58
4.7 Base band part ..........................................................61
4.8 Charger Troubleshooting ............................................63
4.9 USB Troubleshooting ..................................................64
4.10 USIM Detect Troubleshooting ....................................66
4.11 Camera Troubleshooting ..........................................68
4.12 Main Keypad Backlight Troubleshooting ....................70
4.13 Sub Keypad Backlight Troubleshooting ......................71
4.14 LCD Troubleshooting ................................................73
4.15 Vibrator ...................................................................74
4.16 Receiver Path ..........................................................75
4.17 Headset path...........................................................77
4.18 Speaker phone path ................................................79
4.19 Main microphone ....................................................81
4.20 Headset microphone ................................................83
5. Downloading ................................................ 85
5.1 Introduction ...............................................................85
5.2 Downloading Procedure .............................................86
5.3 Troubleshooting Download Errors ..............................101
5.4 Caution ...................................................................106
6. Block Diagram ...........................................107
7. CIRCUIT DIAGRAM ...................................... 109
8. BGA Pin Map ..............................................117
9. PCB LAYOUT ............................................... 121
10. CALIBRATION ............................................ 127
10.1 Confi guration of directory .......................................127
10.2 How to use Tachyon ...............................................129
11. EXPLODED VIEW & REPLACEMENT
PART LIST ................................................ 131
11.1 EXPLODED VIEW ...................................................131
11.2 Replacement Parts ................................................133
11.3 Accessory ............................................................. 150
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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
1. INTRODUCTION
1. INTRODUCTION
BL20
1.1. Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of this model.
1.2. Regulatory Information
A. Security
Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for example,
persons other than your company’s employees, agents, subcontractors, or person working on your
company’s behalf) can result in substantial additional charges for your telecommunications services.
System users are responsible for the security of own system.
There are may be risks of toll fraud associated with your telecommunications system. System users
are responsible for programming and configuring the equipment to prevent unauthorized use. The
manufacturer does not warrant that this product is immune from the above case but will prevent
unauthorized use of common carrier telecommunication service of facilities accessed through or
connected to it. The manufacturer will not be responsible for any charges that result from such
unauthorized use.
B. Incidence of Harm
If a telephone company determines that the equipment provided to customer is faulty and possibly
causing harm or interruption in service to the telephone network, it should disconnect telephone
service until repair can be done. A telephone company may temporarily disconnect service as long as
repair is not done.
C. Changes in Service
A local telephone company may make changes in its communications facilities or procedure. If these
changes could reasonably be expected to affect the use of the phones or compatibility with the net
work, the telephone company is required to give advanced written notice to the user, allowing the user
to take appropriate steps to maintain telephone service.
D. Maintenance Limitations
Maintenance limitations on the phones must be performed only by the manufacturer or its authorized
agent. The user may not make any changes and/or repairs expect as specifically noted in this manual.
Therefore, note that unauthorized alternations or repair may affect the regulatory status of the system
and may void any remaining warranty.
E. Notice of Radiated Emissions
This model complies with rules regarding radiation and radio frequency emission as defined by local
regulatory agencies. In accordance with these agencies, you may be required to provide information
such as the following to the end user.
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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
BL20
F. Pictures
The pictures in this manual are for illustrative purposes only; your actual hardware may look slightly
different.
G. Interference and Attenuation
A phone may interfere with sensitive laboratory equipment, medical equipment, etc. Interference from
unsuppressed engines or electric motors may cause problems.
H. Electrostatic Sensitive Devices
ATTENTION
Boards, which contain Electrostatic Sensitive Device (ESD), are indicated by the sign. Following
information is ESD handling:
• Service personnel should ground themselves by using a wrist strap when exchange system boards.
• When repairs are made to a system board, they should spread the floor with anti-static mat which is
also grounded.
• Use a suitable, grounded soldering iron.
• Keep sensitive parts in these protective packages until these are used.
• When returning system boards or parts like EEPROM to the factory, use the protective package as
described.
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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
2. PERFORMANCE
2.1 Product Name
GU280 : WCDMA2100+EGSM/GSM850/DCS/PCS
(GPRS Class 12 / EDGE Class 12)
2.2 Supporting Standard
WAP 2.0, JAVA(MIDP 2.1 CLDC 1.1)Application Standard
WCDMA(FDD1) TX : 1920 – 1980 MHz
WCDMA(FDD1) RX : 2110 – 2170 MHz
EGSM TX : 880 – 915 MHz
EGSM RX : 925 – 960 MHz
GSM850 TX : 824 – 849 MHz
GSM850 RX : 869 – 894 MHz
DCS1800 TX : 1710 – 1785 MHz
DCS1800 RX : 1805 – 1880 MHz
PCS1900 TX : 1850 – 1910 MHz
PCS1900 RX : 1930 – 1990 MHz
Frequency Range
WCDMA(FDD1)/EGSM/GSM850/DCS1800/PCS1900
with seamless handover
Phase 2+(include AMR)
SIM Toolkit : Class 1, 2, 3, C-E
Supporting Standard
CommentFeatureItem
2.3 Main Parts : Solution
QSC6240 : QualcommRF Chip
QSC6240 : QualcommAnalog Baseband
QSC6240 is an one-chip
solution(DB + AB + RF +
PM)
QSC6240 : QualcommDigital Baseband
CommentPart NameItem
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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
EDGE Class 12EDGE compatibility
GPRS Class 12GPRS compatibility
E2 (GSM900)
E2 (PCS)
E2 (DCS)
GSM 900 : 27 dBm
DCS 1800 : 26 dBm
PCS 1900 : 26 dBm
EDGE
Class3(WCDMA)
Class4 (EGSM)
Class4 (GSM850)
Class1 (PCS)
Class1 (DCS)
WCDMA : 24dBm/3.84MHz,+1/-3dBm
EGSM : 33dBm
GSM850 : 33 dBm
DCS 1800 : 30 dBm
PCS 1900 : 30 dBm
WCDMA/
GSM/
GPRS
TX output
power
WCDMA(FDD1) < -105 dBm
EGSM < -105 dBm
GSM850 < -105 dBm
DCS 1800 < -105 dBm
PCS 1900 <-105 dBm
RX sensitivity
@ Power Level 5 (2G)
@ Tx = 12dBm (3G)
2G : Over 180mins
3G : Over 180 mins
Talk time
@ Power Off / 900mAh3 hrsCharging time
@ Paging Period 5 (2G)
@ DRX 1.28 (3G)
2G : Over 320 hrs
3G : Over 250 hrs
Stand by time
Staggered 10 Layers , 0.8tPCB
TBDVolume
With Battery115gWeight
Standard :
96.0 x 45.7 x 14.9mm
Size
2) Packing Type : Inner Pack
1) Capacity
Standard : Li-Ion, 900mAh
Battery
Slide typeForm Factor
CommentFeatureItem
2.4 Feature
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Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
NoT-Flash
(External Memory)
OptionData Cable
OptionStereo Headset
NoCDROM
YesTravel Adapter
YesSpeaker Phone mode
Support
YesVoice Recording
MPEG4, H.263, Camcorder
MPEG4, H.263, WMV9Video Player
MP3/ WMA/AAC/HE-AAC/EAAC+Music Player
EDR 2.0Blue Tooth
Built in VibratorVibrator
NoData & Fax
FR, EFR, HR,AMRSpeech coding
NAND Flash : 1Gbit
SDRAM : 512Gbit
Memory
YesPC synchronization
3.5Phi, 4 Pole, StereoEar Phone Jack
5 PinSystem connector
Main : Internal Fixed TypeANT
Slide Key pad : 11
Main Key pad : 15
Keypad
1.3 CMOS Camera Built-in Camera
Main LCD
TFT Main LCD(2’, 176 x 220)
Display
Plug-In SIM
3V /1.8V
SIM card type
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LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
2.5 HW Spec.
GSM Transmitter/Receiver spec.
Item Specification
Phase Error
Rms : 5°
Peak : 20 °
Frequency Error
GSM : 0.1 ppm
DCS/PCS : 0.1 ppm
EMC(Radiated Spurious Emission
Disturbance)
GSM/DCS : < -28dBm
Transmitter Output power and Burst
Timing
GSM : 5dBm – 33dBm ± 3dB
DCS/PCS : 0dBm – 30dBm ± 3dB
Burst Timing <3.69us
Spectrum due to modulation out to less
than 1800kHz offset
200kHz : -36dBm
600kHz : -51dBm/-56dBm
Spectrum due to modulation out to larger
than 1800kHz offset to the edge of the
transmit band
GSM :
1800-3000kHz :< -63dBc(-46dBm)
3000kHz-6000kHz : <-65dBc(-46dBm)
6000kHz < : < -71dBc(-46dBm)
DCS :
1800-3000kHz :< -65dBc(-51dBm)
6000kHz < : < -73dBc(-51dBm)
Spectrum due to switching transient
400kHz : -19dBm/-22dBm(5/0), -23dBm
600kHz : -21dBm/-24dBm(5/0), -26dBm
Reference Sensitivity – TCH/FS Class II(RBER) : -105dBm(2.439%)
Usable receiver input level range 0.012(-15 - -40dBm)
Intermodulation rejection – Speech
channels
± 800kHz, ± 1600kHz
: -98dBm/-96dBm (2.439%)
AM Suppression
-GSM : -31dBm - DCS : -29dBm
-98dBm/-96dBm (2.439%)
Timing Advance ± 0.5T
- 11 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
2. PERFORMANCE
WCDMA Transmitter spec.
Item Specification
Transmit Frequency
1920 MHz ~ 1980 MHz
Maximum Output Power
+24 dBm / 3.84 MHz, +1 / -3 dB
Frequency Error within ±0.1 PPM
Open Loop Power
Control
Normal Conditions : within ±9 dB,
Extreme Conditions : within ±12 dB
Minimum Transmit Power
< -50 dBm /3.84 MHz
Occupied Bandwidth
< 5 MHz at 3.84 Mcps (99% of power)
Adjacent Channel
Leakage
Power Ratio (ACLR)
> 33 dB @ ±5 MHz,
> 43 dB @ ±10 MHz
Spurious Emissions
|f-f
c
| > 12.5 MHz
< -36 dBm / 1 kHz RW @ 9 kHz f < 150 kHz
< -36 dBm / 10 kHz RW @ 150 KHz f < 30 MHz
< -36 dBm / 100 kHz RW @ 30 MHz f < 1 GHz
< -30 dBm / 1 MHz RW @ 1 GHz f < 12.75 GHz
< -41 dBm / 300 kHz RW @ 1893.5 MHz < f < 1919.6 MHz
< -67 dBm / 100 kHz RW @ 925 MHz f 935 MHz
< -79 dBm / 100 kHz RW @ 935 MHz < f 960 GHz
< -71 dBm / 100 kHz RW @ 1805 MHz f 1880 MHz
Transmit Intermodulation < -31 dBc @ 5 MHz & < -41 dBc @ 10 MHz
when Interference CW Signal Level = -40 dBc
Error Vector Magnitude < 17.5 %, when Pout -20 dBm
Peak Code Domain Error
< -15 dB at Pout t -20 dBm
- 12 -
LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
WCDMA Receiver spec.
Item Specification
Receive Frequency 2110MHz ~ 2170 MHz
Reference Sensitivity Level BER < 0.001 when Î
or
= -106.7 dBm / 3.84 MHz
Maximum Input Level BER < 0.001 when Î
or
= -25 dBm / 3.84 MHz
Adjacent Channel Selectivity
(ACS)
ACS > 33 dB where BER < 0.001 when Î
or
= -92.7 dBm / 3.84 MHz
& I
oac
= –52 dBm / 3.84 MHz @ ±5 MHz
Blocking Characteristic BER < 0.001 when Î
or
= -103.7 dBm / 3.84 MHz
& I
blocking
= -56 dBm / 3.84 MHz @ Fuw(offset) = ±10 MHz
or I
blocking
= -44 dBm / 3.84 MHz @ Fuw(offset) = ±15 MHz
Spurious Response BER < 0.001 when Î
or
= -103.7 dBm / 3.84 MHz & I
blocking
= -44 dBm
Intermodulation BER < 0.001 when Î
or
= -103.7 dBm / 3.84 MHz
& I
ouw1
= -46 dBm @ F
uw1
(offset) = ±10 MHz
& I
ouw2
= -46 dBm / 3.84 MHz @ F
uw2
(offset) = ±20 MHz
Spurious Emissions < -57 dBm / 100 kHz BW @ 9 kHz f < 1 GHz
< -47 dBm / 1 MHz BW @ 1 GHz f 12.75 GHz
Inner Loop Power Control
In Uplink
Adjust output(TPC command)
cmd 1dB 2dB 3dB
+1 +0.5/1.5 +1/3 +1.5/4
0 -0.5/+0.5 -0.5/+0.5 -0.5/+0.5
-1 -0.5/-1.5 -1/-3 -1.5/-4
group(10equal command group)
+1 +8/+12 +16/+24
- 13 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
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LGE Internal Use Only
3. Technical Brief
3. Technical Brief
3.1. General Description
The RF platform of GU280 supports two different communication modes (WCDMA/GSM modes)
including five communication bands (W2100/W850/GSM850/GSM900/GSM1800/GSM1900).
The all the RF blocks can be divided into three main parts, which are a WCDMA part, a GSM, and
a Antenna switch module.
The simplified block diagram is shown in Figure 1.1.1
Figure 1.1.1 Block diagram of RF part
- 14 -
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Only for training and service purposes
3. Technical Brief
3.2. WCDMA Part
The W-CDMA transceiver uses differential analog in-phase and quadrature-phase interfaces,
that is an IQ-interface, both in the receiver and transmitter information path.
The transceiver has the following general features:
. Power class : Power class 3 (+24dBm) in Band II and V
. Zero-IF Receiver.No IF filter needed
. Direct IQ modulation transmitter
Figure 1.2.1. WCDMA RF structure
- 15 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. Technical Brief
3.2.1. Transmitter Part
WCDMA Transmitter Block
The QSC62x0 device supports tri-band UMTS transmissions with three separate driver amplifier outputs; in fact,
most Tx active circuits are contained within the device. All three UMTS transmit paths (Figure 1.2.1.1) begin with a
single, shared analog baseband signal from the device’s baseband circuits. The baseband signal is composed of
two differential lines, one in-phase component and one quadrature-phase component. Each component is lowpass
filtered and amplified to levels sufficient for driving the quadrature upconverters. There are two upconverters —
one for low-band signals and one for high band — but only one upconverter is active at a time.
Figure 1.2.1.1 WCDMA Transceiver Architecture
The active upconverter’s output is at the desired RF channel frequency and drives the QSC output stages.
These RF circuits include multiple variable-gain stages that provide transmit AGC control.
A greater than 81 dB gain control range is realized using information from the on-chip Tx power detector combined
with a control signal from the baseband circuits. The wide range of driver amplifier output levels is achieved
while supporting the WCDMA standard’s requirements for ACLR, spurious emissions, Rx-band noise, etc.
The high-band driver amplifier output is followed by a SPDT switch that provides two high-band outputs,
thereby fulfilling the tri-band UMTS requirement. The low-band output port is driven directly by its output amplifier.
All three output ports are single-ended with 50ohm nominal impedance. Each requires a matching network to
interface with its band-pass filter.
Each of the three UMTS Tx output chains are functionally identical: the QSC Tx output drives the PA through
the band-pass filter and a matching network; a directional coupler provides a sample of the PA output signal;
the through path of the coupler is routed to the Tx port of the duplexer; the duplexer antenna port is connected to
the antenna switch; and the switch is connected to the antenna.
The coupler outputs provide a low-level sample of the active transmitter’s Tx power. An on-chip power-detector
circuit provides a Tx power estimate that assists in setting the transmit gains and helps ensure that the maximum
allowed output power is not exceeded. The three UMTS couplers (one for each band) use a daisy-chain configuration
that allows them to share the single, on-chip power detector circuit.
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3. Technical Brief
3.2.2. Receiver Part
WCDMA Receiver
The antenna collects the base station forward-link signal and radiates the phone’s reverse-link signal. In the example of
a multiband, multimode phone (Figure 1.2.2.1), a switch routes the antenna signals to one of the three UMTS Rx/Tx paths,
each beginning with its own band-specific duplexer that separates that band’s receive and transmit paths
Figure 1.2.2.1 WCDMA Receiver schematic
Each UMTS duplexer provides a differential output signal that is compatible with its QSC LNA input.
The duplexer-to-LNA interface requires a differential matching network (MN) that optimizes the power transfer into
the LNA.
Although there are three UMTS LNAs, only one is active at a time. The active gain-stepped LNA output drives a
shared quadrature downconverter directly — an off-chip inter-stage filter is not required. The elimination of this
filter is achieved by a combination of factors:
- New on-chip QSC processing
- Higher performance achieved by the differential duplexer-to-LNA interface
-Greater duplexer suppression of Tx leakage
The downconverter’s RF circuitry includes another gain-stepped amplifier that supplements the LNA gain steps to
further extend the receiver dynamic range. The downconverter translates the active LNA’s RF signal directly to
baseband, producing two analog outputs: in-phase (I) and quadrature (Q). The UMTS baseband signals are routed
to lowpass filters whose passband and stopband characteristics are optimized for the active WCDMA waveform.
Both filter outputs are buffered to drive their analog-to-digital converters for digitization. The digital baseband
outputs are routed to QSC baseband circuits for further processing.
- 17 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
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LGE Internal Use Only
3. Technical Brief
3.2.3. Power Amplifier Module
The ACPM-5201 is a fully matched 10-pin surface mount module developed for UMTS Band1.
This power amplifier module operates in the 1920-1980MHz bandwidth.
The ACPM-5001 meets stringent UMTS linearity requirements up to 27.5dBm output power.
The 3mmx3mm form factor package is self contained, incorporating 50ohm input and output matching
Networks The ACPM-5201 features 5th generation of CoolPAM circuit technology which supports 3 power modes
– bypass, mid and high power modes. The CoolPAM is stage bypass technology enhancing PAE (power added
efficiency) at low and medium power range. Active bypass feature is added to 5th generation to enhance PAE
further at low output range. This helps to extend talk time. A directional coupler is integrated into the module and
both coupling and isolation ports are available externally, supporting daisy chain.
The power amplifier is manufactured on an advanced InGaP HBT (hetero-junction Bipolar Transistor)
MMIC (microwave monolithic integrated circuit) technology offering state-of-the-artreliability, temperature stability
and ruggedness.
Figure 1.2.3.1 ACPM-5201 Functional Block Diagram
- 18 -
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3. Technical Brief
Figure 1.2.3.2 WCDMA PAM schematic
1880,1960MHz
B7686FL101
79
25
4
8
1
36
ANT TX_IN
RX_OUT1
RX_OUT2
GND1
GND2 GND4
GND3 GND5
R103
49.9
2
1
C138 2.2p
1
2
C142 1.8n
2
1
C117 33p
1
2
2.7nC118
2
1
DNI
C159
1
2
L107
10n
0
C123
2
1
DNIC181
1
2
L108 33p
1
2
L109 33p
1
2
0.5p
C124
1
2
L110 DNI
1
2
FL102
836.5MHz
B9425
532
41
IN
OUT
G1G2G3
DNI
C156
1
2
L111
DNI
1
2
2.2pC134
1
2
DNI
C127
1
2
1nC128
2
1
DNI C129
1
2
001
70
1
R
2
1
801R
001
2
1
2.2u
C130
1
2
DNI
C132
1
2
DNI C133
1
2
0.5p
L122
1
2
3.3nC144
2
1
L121
DNI
1
2
1.8nC116
2
1
C135
DNI
1
2
DNI
C136
1
2
0
411R
2
1
1p
L115
1
2
C139
1n
1
2
1n
C140
1
2
DNI
C141
1
2
DNIC125
1
2
DNIL116
1
2
DNI
L117
1
2
DNIL123
1
2
33p
C143
1
2
L119
DNI
2
1
4.7pL120
1
2
C149 DNI
1
2
C145
680p
1
2
C146
680p
1
2
+VPWR+VPWR
C147
330p
1
2
C126
0
2
1
R109
68
2
1
+VPWR
B7671FL103
836.5 MHz,881.5 MHz
95
7
3
1
2
8
4
6
ANT
GND2
RX_OUT2
GND1
RX_OUT1
TX_IN
GND4
GND3 GND5
10n
L118
2
1
4.7n
C150
2
1
12n
C160
2
1
ACPM-5201 U102
65
74
83
92
10 1
11
PGND
VCC1VCC2
RFINRFOUT
VBPISO
VMODEGND
VENCPL
1.5nC119
2
1
2.2u
C151
1
2
L124
DNI
1
2
C155
1n
1
2
C137
DNI
1
2
B9414FL104
1950MHz
532
41
IN
OUT
G1G2G3
C158
330p
1
2
+VPWR
8.2pC148
1
2
6.8nR111
2
1
B7696
FL106
1950 MHz,2140 MHz
95
74
1
2
8
36
ANT
TX_IN
RX_OUT2
GND1
RX_OUT1
GND2 GND4
GND3 GND5
DNI
L125
2
1
U104ACPM-5305
65
74
83
92
10 1
11
PGND
VENCPL
VMODEGND
VBPISO
RFINRFOUT
VCC1VCC2
DNI
C173
1
2
C180
DNI
1
2
PA_R0
PA_R0
WLNA_HB2_IN_M
WLNA_HB2_IN_P
WLNA_LB_IN_P
WLNA_LB_IN_M
WCDMA_2100_TX_OUT
WCDMA_900_TX_OUT
WLNA_HB1_IN_M
WLNA_HB1_IN_P
WCDMA_PA_ON1
PWR_DET
PA_R1
PA_R1
WCDMA_2100
PCS_IN_P
PCS_IN_M
WCDMA_LB
WCDMA_PA_ON0
WCDMA_1900
WCDMA_1900_TX_OUT
WCDMA_1900
WCDMA_2100
WCDMA_850/900
WCDMA_2100
WCDMA_850/900
WCDMA_1900
- 19 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
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3. Technical Brief
3.3. EDGE/GPRS/GSM RF block
The EDGE/GPRS/GSM transceiver use a digital interface that is shared between receive and transmit data.
The receive interface is based on I and Q data and the transmitter interface is based on envelop and frequency data.
The quad band EDGE/GSM/GPRS transceiver has the following general features:
Power class
GMSK low bands: Class 4 (33 dBm)
GMSK high bands: Class 1 (30 dBm)
8PSK low bands: Class E2 (27 dBm)
8PSK high bands: Class E2 (26 dBm)
Multi slot class 12 (4+4=5)
Dual Transfer Mode (DTM) class 9 (3+2=5)
Zero-IF receiver
-Polar modulation transmitter
3.3.1. Transmitter Part
GSM/EDGE Transmitter Block
The QSC62x0 device supports quad-band GSM transmissions with two separate dual-band driver amplifier outputs; in
fact, most Tx active circuits are contained within the device. Both GSM transmit paths (Figure 1.3.1.1) begin with a
single, shared analog baseband signal from the device’s baseband circuits — the same interface and baseband
circuits used by the UMTS transmitters. The GSM transmitters use the same quadrature upconverters as well — one
for low band signals and one for high band — with just one active at a time. The transmitter LO signals are generated
by circuits described in next section and delivered to the upconverter circuits at the correct frequency, with the
proper phase relationship, and with an adequate drive level.
The SPDT switches at each driver amplifier input allow selection of the output signal: either the actual GSM signal
from the upconverter or a test signal generated by the Tx LO synthesizer. The Tx output chain is functionally identical
for both the low band and the high band: the power amplifier is driven by the QSC device through a matching
network and a resistive attenuator; the PA output is routed to the antenna switch module whose output is connected
to the antenna.
In addition to the through signal path, the QSC device also provides the PA ramp control signal that ensures smooth
transitions while the transmitter is turned on and off for GSM’s burst transmissions.
The ramp signal is generated by one of the baseband circuit’s Tx DACs. A switch after the baseband amplifier selects
whether the DAC output signal is routed to GSM PA module for ramping the PA up or down, or to the transmitter
signal path for data transmission.
- 20 -
LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. Technical Brief
Figure 1.3.1.1 QSC GSM transmitter signal paths functional diagram
3.3.2. Receiver Part
There are two recommended GSM receiver path configurations; both are shown in Figure 1.3.2.1.
The configuration shown on top allows the GSM 850 and GSM 1900 bands to share the UMTS 850 and UMTS 1900
paths for US applications and uses four LNA inputs to support quad-band GSM operation.
The lower example uses two LNAs for quad-band GSM operation (one low band and one high band),
with two-way SAW filters between the antenna switch and the QSC inputs for each band type.
- 21 -
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
LGE Internal Use Only
3. Technical Brief
Figure 1.3.2.1 QSC GSM receiver signal paths functional diagram
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LG GU285 User manual

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