LG KS10 User manual

Date: July, 2007 / Issue 1.0
Service Manual Model : KS10
Service Manual
KS10
Internal Use Only

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1. INTRODUCTION.................................. 5
1.1 Purpose ...................................................... 5
1.2 Regulatory Information ............................... 5
2. PERFORMANCE ..................................7
2.1 System Overview.........................................7
2.2 Usable environment.....................................8
2.3 Radio Performance......................................8
2.4 Current Consumption.................................14
2.5 RSSI BAR ..................................................14
2.6 Battery BAR ...............................................15
2.7 Sound Pressure Level ...............................16
2.8 Charging ....................................................16
3. TECHNICAL BRIEF............................17
3.1 General Description ...................................17
3.2 GSM Mode.................................................19
3.3 UMTS Mode...............................................23
3.4 LO Phase-locked Loop ..............................26
3.5 Off-chip RF Components ...........................29
3.6 Digital Baseband
(Stn8810 / MSM6275)................................34
3.7. Hardware Architecture ..............................36
3.8. Subsystem of STn8810 ............................39
3.9. Hardware Peripheral system of
Stn8810 ....................................................42
3.10. Subsystem of MSM6275.........................47
3.11. External memory interface......................50
3.12. Hardware sub system of MSM6275........51
3.13. Audio and sound.....................................61
3.14. Camera interface ....................................67
3.15 Bluetooth..................................................76
3.16 Main Features..........................................77
4. TROUBLE SHOOTING.......................83
4.1 RF Component ..........................................83
4.2 SIGNAL PATH ...........................................85
4.3 Checking VCXO Block...............................87
4.4 Checking Ant. Switch Module Block ..........91
4.5 Checking WCDMA Block ...........................93
4.6 Checking GSM Block...............................103
4.7 Power on trouble......................................111
4.8 USB trouble .............................................114
4.9 SIM detect trouble....................................115
4.10 Key sense trouble ..................................116
4.11 Keypad backlight trouble .......................118
4.12 Folder on/off trouble...............................120
4.13 Micro SD trouble ....................................122
4.14 Charging trouble ....................................124
4.15 Audio trouble..........................................127
4.16 Camera trouble ......................................143
4.17 Main LCD trouble...................................149
4.18 Bluetooth trouble....................................152
5. DOWNLOAD.....................................155
5.1 Composition omposition ..........................155
5.2 LGDP2 Program install LGDP2 Program
install........................................................156
5.3 USB Driver setup USB Driver setup ........159
5.4 KS10 LGDP2 run file & DLL file setup .....162
5.5 Execute LGDP2 program.........................163
6. BLOCK DIAGRAM ...........................178
6.1 GSM & WCDMA RF Block.......................178
6.2 Interface Diagram ....................................180
6.3 KS10 Modem & Baseband
Block Diagram .........................................184
6.4 KS10 Application Processor Block
Diagram ...................................................185
6.5 KS10 Audio & BT Block Diagram ............186
Table Of Contents
LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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6.6 KS10 Camera Block Diagram .................187
6.7 KS10 LCD Block Diagram ......................188
6.8 KS10 Power Distribution Diagram ...........189
6.9 KS10 Clock Distribution Diagram ...........190
7. Circuit Diagram................................177
8. PCB LAYOUT ...................................202
9. Usage of Hot-Kimchi .......................209
9.1 Usage of Hot-Kimchi................................195
10. Engineering Mode .........................212
10.1 Version Info............................................213
10.2 Device Test............................................213
10.3 Factory Reset ........................................214
10.4 MTC .......................................................214
10.5 Save Log................................................214
11. EXPLODED VIEW & REPLACEMENT
PART LIST ..................................... 216
10.1 EXPLODED VIEW ................................ 216
10.2 Replacement Parts
<Mechanic component> ....................... 219
<Main component> ............................... 222
10.3 Accessory ............................................. 246
LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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 commoncarrier 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.
1. INTRODUCTION
1. INTRODUCTION

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LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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.
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.
1. INTRODUCTION

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LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. PERFORMANCE
2.1 System Overview
2. PERFORMANCE
Item Specification
Shape GSM900/1800/1900 and WCDMA Slide Handset
Size 104 X 52 X 18.9 mm
Weight 118 g (with 950mAh Battery)
Power 3.7V normal, 950 mAh Li-Polymer
Talk Time Over 150 min (WCDMA, Tx=12 dBm, Voice)
(with 950mAh) Over 175 min (GSM, Tx=Max, Voice)
Standby Time Over 200 Hrs (WCDMA, DRX=1.28)
(with 950mAh) Over 220 Hrs (GSM, Paging period=9)
Antenna Internal type and Antenna
LCD Main 240 X 320 pixel TFT (QVGA LCD Module)
LCD Backlight Blue LED Back Light (main only)
Camera Dual Camera ; 1.3 Mega pixel (CMOS), VGA Camera (CMOS)
Vibrator Yes (Cylinder Type)
LED Indicator No
MIC Yes
Receiver Yes
Earphone Jack Yes
Connectivity Bluetooth, USB
Volume Key Push Type(+, -)
External Memory Micro-SD
I/O Connect 18 Pin

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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2.2 Usable environment
1) Environment
2) Environment (Accessory)
* CLA : 12 ~ 24 V(DC)
2.3 Radio Performance
1) Transmitter - GSM Mode
* In case of DCS : [A] -> 1710, [B] -> 1785 * In case of PCS : [A] -> 1850, [B] -> 1910
2. PERFORMANCE
Item Specification
Voltage 3.7 V(Typ), [Shut Down : 3.22 V]
Operation Temp -20 ~ +60°C
Storage Temp -20 ~ +70°C
Humidity 85 % (Max)
Reference Spec. Min Typ. Max Unit
TA Power Available power 100 220 240 Vac
No Item GSM DCS & PCS
100k~1GHz -39dBm
9k ~ 1GHz -39dBm
MS allocated 1G~[A]MHz -33dBm
Channel
1G~12.75GHz -33dBm
[A]M~[B]MHz -39dBm
Conducted [B]M~12.75GHz -33dBm
1Spurious 100k~880MHz -60dBm 100k~880MHz -60dBm
Emission 880M~915MHz -62dBm 880M~915MHz -62dBm
Idle Mode
915M~1GHz -60dBm 915M~1GHz -60dBm
1G~[A]MHz -50dBm 1G~[A]MHz -50dBm
[A]M~[B]MHz -56dBm [A]M~[B]MHz -56dBm
[B]M~12.5GHz -50dBm [B]M~12.5GHz -50dBm

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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2. PERFORMANCE
* In case of DCS : [A] -> 1710, [B] -> 1785 * In case of PCS : [A] -> 1850, [B] -> 1910
No Item GSM DCS & PCS
30M ~ 1GHz -36dBm
30M~1GHz -36dBm
MS allocated 1G~[A]MHz -30dBm
Channel
1G ~ 4GHz -30dBm
[A]M~[B]MHz -36dBm
Radiated [B]M~4GHz -30dBm
2Spurious 30M ~ 880MHz -57dBm 30M~880MHz -57dBm
Emission 880M ~ 915MHz -59dBm 880M~915MHz -59dBm
Idle Mode
915M~1GHz -57dBm 915M~1GHz -57dBm
1G~[A]MHz -47dBm 1G~[A]MHz -47dBm
[A]M~[B]MHz -53dBm [A]M~[B]MHz -53dBm
[B]M~4GHz -47dBm [B]M~4GHz -47dBm
3Frequency Error ±0.1ppm ±0.1ppm
4Phase Error
±5(RMS) ±5(RMS)
±20(PEAK) ±20(PEAK)
3dB below reference sensitivity 3dB below reference sensitivity
Frequency Error RA250 : ±200Hz RA250: ±250Hz
5Under Multipath and HT100 : ±100Hz HT100: ±250Hz
Interference Condition TU50 : ±100Hz TU50: ±150Hz
TU3 : ±150Hz TU1.5: ±200Hz
0 ~ 100kHz +0.5dB 0 ~ 100kHz +0.5dB
200kHz -30dB 200kHz -30dB
250kHz -33dB 250kHz -33dB
Due to 400kHz -60dB 400kHz -60dB
Output RF
modulation 600 ~ 1800kHz -60dB 600 ~ 1800kHz -60dB
61800 ~ 3000kHz -63dB 1800 ~ 6000kHz -65dB
Spectrum
3000 ~ 6000kHz -65dB ≥6000kHz -73dB
≥6000kHz -71dB
Due to
400kHz -19dB 400kHz -22dB
Switching
600kHz -21dB 600kHz -24dB
transient
1200kHz -21dB 1200kHz -24dB
1800kHz -24dB 1800kHz -27dB

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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2. PERFORMANCE
No Item GSM DCS & PCS
Frequency offset 800kHz
7Intermodulation attenuation –
Intermodulation product should
be Less than 55dB below the
level of Wanted signal
Power control Power Tolerance Power control Power Tolerance
Level (dBm) (dB) Level (dBm) (dB)
533±3 030±3
631±3 128±3
729±3 226±3
827±3 324±3
925±3 422±3
10 23 ±3 5 20 ±3
8Transmitter Output Power 11 21 ±3 6 18 ±3
12 19 ±3 7 16 ±3
13 17 ±3 8 14 ±3
14 15 ±3 9 12 ±4
15 13 ±3 10 10 ±4
16 11 ±5 11 8 ±4
17 9 ±5 12 6 ±4
18 7 ±5 13 4 ±4
19 5 ±5 14 2 ±5
15 0 ±5
9Burst timing Mask IN Mask IN

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2. PERFORMANCE
2) Transmitter - WCDMA Mode
No Item Specification
1Maximum Output Power Class 3 : +24dBm(+1/-3dB)
Class 4 : +21dBm(±2dB)
2Frequency Error ±0.1ppm
3Open Loop Power control in uplink ±9dB@normal, ±12dB@extreme
Adjust output(TPC command)
cmd 1dB 2dB 3dB
+1 +0.5/1.5 +1/3 +1.5/4.5
4Inner Loop Power control in uplink 0 -0.5/+0.5 -0.5/+0.5 -0.5/+0.5
-1 -0.5/-1.5 -1/-3 -1.5/-4.5
Group (10 equel command group)
+1 +8/+12 +16/+24
5Minimum Output Power -50dBm(3.84MHz)
Qin/Qout : PCCH quality levels
6Out-of-synchronization handling of output power Toff@DPCCH/Ior : -22 -> -28dB
Ton@DPCCH/Ior : -24 -> -18dB
7Transmit OFF Power -56dBm(3.84MHz)
8Transmit ON/OFF Time Mask
±25us
PRACH,CPCH,uplinlk compressed mode
±25us
9Change of TFC
Power varies according to the data rate
DTX : DPCH off
(minimize interference between UE)
10 Power setting in uplink compressed ±3dB(after 14slots transmission gap)
11 Occupied Bandwidth(OBW) 5MHz(99%)
-35-15*(∆f-2.5)dBc@∆f=2.5~3.5MHz,30k
12 Spectrum emission Mask
-35-1*(∆f-3.5)dBc@∆f=3.5~7.5MHz,1M
-39-10*(∆f-7.5)dBc@∆f=7.5~8.5MHz,1M
-49dBc@∆f=8.5~12.5MHz,1M

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3)Receiver - GSM Mode
2. PERFORMANCE
No Item Specification
13 Adjacent Channel Leakage Ratio(ACLR)
33dB@5MHz, ACP>-50dBm
43dB@10MHz, ACP>-50dBm
-36dBm@f=9~150KHz, 1K BW
-36dBm@f=50KHz~30MHz, 10K BW
-36dBm@f=30MHz~1000MHz, 100K BW
14
Spurious Emissions -30dBm@f=1~12.5GHz, 1M BW
(*: additional requirement) (*)-41dBm@f=1893.5~1919.6MHz, 300K
(*)-67dBm@f=925~935MHz, 100K BW
(*)-79dBm@f=935~960MHz, 100K BW
(*)-71dBm@f=1805~1880MHz, 100K BW
15 Transmit Intermodulation
-31dBc@5MHz,Interferer -40dBc
-41dBc@10MHz, Interferer -40dBc
16 Error Vector Magnitude (EVM)
17.5%(>-20dBm)
(@12.2K, 1DPDCH+1DPCCH)
17 Transmit OFF Power
-15dB@SF=4.768Kbps, Multi-code
transmission
No Item GSM DCS & PCS
1 Sensitivity (TCH/FS Class II) -105dBm -105dBm
2
Co-Channel Rejection
C/Ic=7dB Storage -30 ~ +85
(TCH/FS Class II, RBER, TU high/FH)
3Adjacent Channel 200kHz C/Ia1=-12dB C/Ia1=-12dB
Rejection 400kHz C/Ia2=-44dB C/Ia2=-44dB
Wanted Signal :-98dBm Wanted Signal :-96dBm
4 Intermodulation Rejection 1st interferer:-44dBm 1st interferer:-44dBm
2nd interferer:-45dBm 2nd interferer:-44dBm
5
Blocking Response Wanted Signal :-101dBm Wanted Signal :-101dBm
(TCH/FS Class II, RBER) Unwanted : Depend on Frequency Unwanted : Depend on Frequency

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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2. PERFORMANCE
4) Receiver - WCDMA Mode
No Item Specification
1Reference Sensitivity Level -106.7 dBm(3.84 MHz)
-25dBm(3.84MHz)
2Maximum Input Level -44dBm/3.84MHz(DPCH_Ec)
UE@+20dBm output power(Class3)
3Adjacent Channel Selectivity (ACS)
33dB
UE@+20dBm output power(Class3)
-56dBm/3.84MHz@10MHz
4In-band Blocking UE@+20dBm output power(Class3)
-44dBm/3.84MHz@15MHz
UE@+20dBm output power(Class3)
-44dBm/3.84MHz@f=2050~2095 and
2185~2230MHz
UE@+20dBm output power(Class3)
-30dBm/3.84MHz@f=2025~2050 and
5Out-band Blocking 2230~2255MHz
UE@+20dBm output power(Class3)
-15dBm/3.84MHz@f=1~2025 and
2255~12500MHz
UE@+20dBm output power(Class3)
6Spurious Response
-44dBm CW
UE@+20dBm output power(Class3)
-46dBm CW@10MHz
7Intermodulation Characteristic -46dBm/3.84MHz@20MHz
UE@+20dBm output power(Class3)
-57dBm@f=9KHz~1GHz, 100K BW
8Spurious Emissions -47dBm@f=1~12.5GHz, 1M BW
-60dBm@f=1920MHz~1980MHz, 3.84M BW
-60dBm@f=2110MHz~2170MHz, 3.84M BW

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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2. PERFORMANCE
2.4 Current Consumption
(Stand by Test Condition : Bluetooth off, LCD backlight off)
(Call Test Condition : Bluetooth off, LCD backlight dimming mode)
(VT Test Condition : Speaker off, LCD backlight On)
2.5 RSSI BAR
Stand by Voice Call VT
WCDMA
Under 4.32 mA Under 335 mA Under 569mA
(DRX=1.28) (Tx=10dBm -Low power) (Tx=10dBm -Low power)
Under 4.32 mA Under 380 mA
GSM (Paging=5period) (Tx=Max power)
Level Change WCDMA GSM
BAR 7 → 6-86 ±2 dBm -82 ±2dBm
BAR 6 → 5-90 ±2 dBm -86 ±2dBm
BAR 5 → 4-94 ±2 dBm -90 ±2dBm
BAR 4 → 3-98 ±2 dBm -94 ±2dBm
BAR 3 → 2-102 ±2 dBm -98 ±2dBm
BAR 2 → 1-106 ±2 dBm -102 ±2dBm
BAR 1 → 0-110 ±2 dBm -106 ±2dBm

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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2.6 Battery BAR
2. PERFORMANCE
Indication Standby
Bar 7 3.96 ± 0.05V
Bar 7 →63.95 ± 0.05V
Bar 6 →53.86 ± 0.05V
Bar 5 →43.78 ± 0.05V
Bar 4 →33.74 ± 0.05V
Bar 3 →23.69 ± 0.05V
Bar 2 →13.63 ± 0.05V
Bar 1 →Empty 3.50 ± 0.05V
Low Voltage, 3.63,3.50 ± 0.05V (Stand-by) / 3.63, 3.50 ± 0.05V (Talk)
Warning message + tone Bar 2 → 1 / Bar 1 →Empty
Power Off 3.20 ± 0.05V

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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2. PERFORMANCE
2.7 Sound Pressure Level
2.8 Charging
- Charging Method : CC & CV (Constant Current & Constant Voltage)
- Maximum Charging Voltage : 4.2V
- Maximum Charging Current : 650mA
- Nominal Battery Capacity : 950 mAh
- Charger Voltage : 4.8V
- Charging time : Max 3 h (Except time trickle charging)
- Full charge indication current (icon stop current) : 60mA
- Low battery POP UP : 3.48V
- Low battery alarm interval : Idle - 3 min, Dedicated - 1min
- Cut-off voltage : 3.22V
No Test Item Specification
1Sending Loudness Rating (SLR) 8 ±3 dB
2Receiving Loudness Rating (RLR) Nor -4 ± 3 dB
Max -15 ± 3 dB
3Side Tone Masking Rating (STMR) Min 17 dB
4Echo Loss (EL) Min 40 dB
5Sending Distortion (SD) Refer to Table 30.3
6Receiving Distortion (RD) Refer to Table 30.4
7Idle Noise-Sending (INS) Max -64 dBm0p
8Idle Noise-Receiving (INR) Nor Under -47 dBPA
Max Under -36 dBPA
9Sending Loudness Rating (SLR) 8±3dB
10 Receiving Loudness Rating (RLR) Nor -1 ±3 dB
Max -12 ±3 dB
11 Side Tone Masking Rating (STMR) Min 25 dB
12 Echo Loss (EL) Min 40 dB
13 Sending Distortion (SD) Refer to Table 30.3
14 Receiving Distortion (RD) Refer to Table 30.4
15 Idle Noise-Sending (INS) Max -55 dBm0p
16 Idle Noise-Receiving (INR) Nor Under -45 dBPA
Max Under -40 dBPA
TDMA Noise
-. GSM : Power Level : 5
DCS/PCS : Power Level : 0
(Cell Power : -90 ~ -105 dBm)
17
-. Acoustic (Max Vol.)
MS/Headset SLR : 8 ± 3dB
MS/Headset RLR : -15 ± 3dB/-12dB
(SLR/RLR : Mid-value setting)
MS
Headset
MS and
Headset
Max Under -62 dBm

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3. TECHNICAL BRIEF
3.1 General Description
The KS10 supports UMTS-2100 DS-WCDMA, EGSM-900, DCS-1800, and PCS-1900. All receivers
and the UMTS transmitter use the radio One1Zero-IF architecture to eliminate intermediate
frequencies, directly converting signals between RF and baseband. The EGSM, DCS1800 and
PCS1900 transmitters use a baseband-to-IF up-conversion followed by an offset phase-locked loop
that translates the GMSK-modulated signal to RF.
1QUALCOMM’s branded chipset that implements a Zero-IF radio architecture.
3. TECHNICAL BRIEF
KS10 high-level RF functional block diagram

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LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
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A generic, high-level functional block diagram of KS10 is shown in Figure 1-1. One antenna collects
base station forward link signals and radiates handset reverse link signals. The antenna connects with
receive and transmit paths through a switch module (plus a duplexer for UMTS-2100 operation).
UMTS band signals at the antenna are switched to the relevant UMTS duplexer. The UMTS receive
band signals are amplified by the front-end LNAs of the RFR6250 IC before passing through a band-
pass filter and being applied to the mixer inputs of the RFR6250 IC. On-chip circuits down-convert the
received signal directly from RF to baseband using radioOne Zero-IF techniques. Generation and
distribution of the UMTS LO, for the down-converter, is performed entirely on-chip (except for the loop
filter). The RFR6250 IC outputs analog baseband signals for processing by the MSM device. This
baseband interface is shared with the RTR6250 GSM receiver outputs, but is separate from the GPS
baseband interface.
EGSM, DCS and PCS receive signals from the antenna switch module pass through their band-pass
filters, then are applied to the RTR6250 IC. In a similar fashion to the UMTS paths, RTR6250 IC
circuits down-convert the received signals directly from RF to baseband. The GSM LO for multiband
down conversion is entirely generated within the RTR6250 IC (PLL and distribution functions) with
exception of the off-chip loop filter. The RTR analog baseband outputs are routed to the MSM6275 IC
for further processing (an interface shared with the RFR UMTS receive paths).
The UMTS transmit path begins with analog baseband signals from the MSM device that drive the
RTR6250 IC. Integrated PLL and VCO circuits generate the Tx LO used in the quadrature upconverter
that translates baseband signals directly to RF. The RTR6250 output driver stages deliver fairly high-
level signals that are filtered and applied to the power amplifiers (PA). The PA output is routed to the
antenna through a duplexer and switch module.
The shared EGSM-900, DCS-1800, and PCS-1900 transmit path begins with the same baseband
interface from the MSM6275 IC that is used for the UMTS band. A single EGSM/DCS/PCS quadrature
upconverter translates the GMSK-modulated signal to a convenient intermediate frequency (IF) that
forms one input to an offset phase-locked loop (OPLL). OPLL functions are split between the
RTR6250 IC and off-chip loop filter and dual Tx VCO circuits, and translate the GMSK-modulated
signal to the desired EGSM-900, DCS-1800 or PCS-1900 channel frequency. This signal is applied to
a dual power amplifier (only one is active at a time). The enabled path continues with the PA, an
automated power control (APC) circuit that samples the transmit power and adjusts its level, the switch
module (which includes a band-appropriate lowpass filter), and the antenna.
KS10 power supply voltages are managed and regulated by the PM6250 Power Management IC. This
versatile device integrates all wireless handset power management, general housekeeping, and user
interface support functions into a single mixed signal IC. It monitors and controls the external power
source and coordinates battery recharging while maintaining the handset supply voltages using low
dropout, programmable regulators.
The device’s general housekeeping functions include an ADC and analog multiplexer circuit for
monitoring on-chip voltage sources, charging status, and current flow, as well as userdefined off-chip
variables such as temperature, RF output power, and battery ID. Various oscillator, clock, and counter
circuits support IC and higher-level handset functions. Key parameters such as under-voltage lockout
and crystal oscillator signal presence are monitored to protect against detrimental conditions.
3. TECHNICAL BRIEF

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Copyright © 2007 LG Electronics. Inc. All right reserved.
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3. TECHNICAL BRIEF
3.2 GSM Mode
3.2.1 GSM Receiver
The Dual-mode KS10’s receiver functions are split between the two RFICs as follows:
• UMTS-2100 operation uses the RFR6250 Receiver ICs to implement the receive signal path,
accepting an RF input and delivering analog baseband outputs (I and Q).
• EGSM-900, DCS-1800, and PCS-1900 modes both use the RTR6250 IC only. Each mode has
independent front-end circuits and down-converters, but they share common baseband circuits (with
only one mode active at a time). All receiver control functions are beginning with SBI2-controlled
parameters.
The EGSM, DCS, and PCS receiver inputs of RTR6250 are connected directly to the transceiver front-
end circuits(filters and antenna switch module). EGSM, DCS, and PCS receiver inputs are similar to
the RFR6250 UMTS Rx input in that they also use differential configurations to improve common-
mode rejection and second-order non-linearity performance.
The balance between the complementary signals is critical and must be maintained from the RF filter
outputs all the way into the IC pins Since EGSM, DCS, and PCS signals are time-division duplex (the
handset can only receive or transmit at one time), switches are used to separate Rx and Tx signals in
place of frequency duplexers - this is accomplished in the switch module.
The EGSM, DCS, and PCS receive signals are routed to the RTR6250 through band selection filters
and matching networks that transform single-ended 50-Ω sources to differential impedances optimized
for gain and noise figure. Similar to the RFR, the RTR input uses a differential configuration to improve
second-order inter-modulation and common mode rejection performance. The RTR6250 input stages
include MSM-controlled gain adjustments that maximize receiver dynamic range.
The amplifier outputs drive the RF ports of the quadrature RF-to-baseband downconverters.
The downconverted baseband outputs are multiplexed and routed to lowpass filters (one I and one Q)
having passband and stopband characteristics suitable for GMSK processing. These filter circuits
include DC offset corrections. The filter outputs are buffered and passed on to the MSM6275 IC for
further processing (an interface shared with the RFR6250 UMTS receiver outputs).
2The RFIC operating modes and circuit parameters are MSM-controlled through the proprietary 3-line Serial Bus Interface (SBI). The Application
Programming Interface (API) is used to implement SBI commands. The API is documented in AMSS Software - please see applicable AMSS
Software documentation for details.

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LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF

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LGE Internal Use Only
Copyright © 2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
3.2.2 GSM Transmitter
The shared GSM Low-band (EGSM900) and High-band (DCS1800, PCS1900) transmit path begins
with the baseband inputs from the MSM6275 IC. These differential analog input signals are buffered,
lowpass filtered, corrected for DC offsets then applied to the GSM quadrature upconverter. The
upconverter LO signals are generated from the transceiver VCO signal by the LO distribution and
generation circuits within RTR6250. This upconverter translates the GMSK-modulated signal to a
convenient intermediate frequency (IF) that forms one input to a frequency/phase detector circuit. This
IF signal is the reference input to an offset phase-locked loop (OPLL) circuit as shown in Figure 1.2.2-1.
The feedback path of this OPLL circuit includes a downconversion from the RF output frequency range
to the IF range. The two inputs to this downconversion mixer are formed as follows:
1. The dual Tx VCO output (operating in the desired RF output frequency range) is buffered within the
RTR6250 IC then applied to the mixer RF port.
2. The LO Generation and Distribution circuits that deliver the transmit path.s LO for the baseband-to-IF
upconversion also provides the offset LO signal that is applied to the feedback path.s mixer LO port.
Figure 1.2.2-1 Offset phase-locked loop interfaces