LG KC550 User manual

Date: May, 2008 / Issue 1.0
Service Manual Model : KC550
Service Manual
KC550
Internal Use Only

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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* The information in this manual is subject to change without notice and should not be construed as a
commitment by LGE Inc. Furthermore, LGE Inc. reserves the right, without notice, to make changes to
equipment design as advances in engineering and manufacturing methods warrant.
* This manual provides the information necessary to install, program, operate and maintain the KC550.
REVISED HISTORY
Editor Date Issue Contents of Changes S/W Version
Y.W.YUN 5/26 0.1

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LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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1. INTRODUCTION ...............................7
1.1 Purpose .................................................. 7
1.2 Regulatory Information............................ 7
1.3 ABBREVIATION ..................................... 9
2. GENERAL PERFORMANCE ..........11
2.1 H/W Features.........................................11
2.2 Technical specification...........................12
3. TECHNICAL BRIEF ........................19
3.1 KC550 Component Block diagram.........19
3.2 Main Chip Introduction ...........................20
3.3 Baseband Part Introduction ...................22
3.4 Power Management Unit .......................38
3.5 Power ON/OFF ......................................43
3.6 SIM interface..........................................47
3.7 Memory ..................................................48
3.8 LCD Display ...........................................50
3.9 Keypad Switching & Scanning ...............53
3.10 Keypad back-light illumination .............54
3.11 LCD back-light illumination ..................55
3.12 JTAG interface connector ....................57
3.13 Audio....................................................58
3.14 USB charging circuit ............................62
3.15 BLUETOOTH .......................................63
3.16 FM Radio..............................................66
3.17 Micro SD external memory card slot....67
3.18 18pin Multi Media Interface
connector .............................................69
4. RF circuit technical brief ...............71
4.1 General Description ...............................71
4.2 Receiver part..........................................73
4.3 Transmitter part......................................74
4.4 RF synthesizer .......................................75
4.5 DCXO.....................................................76
4.6 Front End Module control.......................76
4.7 Power Amplifier Module .........................77
4.8 Mode Selection ......................................78
5. PCB layout......................................79
5.1 Main PCB component placement ..........79
6. Trouble shooting............................84
6.1 Trouble shooting test setup....................84
6.2 Power on Trouble...................................85
6.3 Charging trouble ....................................88
6.4 LCD display trouble................................90
6.5 Camera Trouble .....................................93
6.6 Receiver & Speaker trouble ...................95
6.7 Microphone trouble ................................97
6.8 Ear-MIc Jack Detection trouble..............98
6.9 Vibrator trouble ......................................99
6.10 Keypad back light trouble...................100
6.11 SIM & uSD trouble .............................103
6.12 RF Troubleshooting ...........................106
6.13 RF Receiver path Troubleshooting ....110
6.14 RF Transmitter path Troubleshooting 113
7. Download & S/W upgrade...............118
7.1 Download program user guide.............118
7.2 Multi-Download Program Setting .........119
8. CIRCUIT DIAGRAM ......................121
9. BGM PIN MAP...............................131
10. PCB LAYOUT..............................137
11. RF Calibration.............................145
11.1 Test Equipment Setup .......................145
11.2 Calibration Step .................................145
12. Stand-alone Test ........................151
12.1 Test Program Setting .........................151
12.2 Tx Test ...............................................153
12.3 Rx Test...............................................154
13. ENGINEERING MODE ................155
14. EXPLODED VIEW &
REPLACEMENT PART LIST ......157
14.1 Exploded View ...................................157
14.2 Replacement Parts ............................159
14.3 Accessory ..........................................182
Table Of Contents

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LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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1. INTRODUCTION
1.1 Purpose
This manual provides the information necessary to repair, calibration, description and download the
features of the KC550.
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 you°Øre 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. LGE
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. LGE 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 KC550 or compatibility with the network,
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 KC550 must be performed only at the LGE or its authorized agents.
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
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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1. INTRODUCTION
E. Notice of Radiated Emissions
The KC550 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
An KC550 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 contains 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 such as EEPROM to the
factory, use the protective package as described.
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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1. INTRODUCTION
1.3 ABBREVIATION
For the purposes of this manual, following abbreviations apply:
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
APC Automatic Power Control
BB Baseband
BER Bit Error Ratio
CC-CV Constant Current - Constant Voltage
CLA Cigar Lighter Adapter
DAC Digital to Analog Converter
DCS Digital Communication System
dBm dB relative to 1 milli-watt
DSP Digital Signal Processing
EEPROM Electrical Erasable Programmable Read-Only Memory
EGPRS Enhanced General Packet Radio Service
EL Electroluminescence
ESD Electrostatic Discharge
FPCB Flexible Printed Circuit Board
GMSK Gaussian Minimum Shift Keying
GPIB General Purpose Interface Bus
GPRS General Packet Radio Service
GSM Global System for Mobile Communications
IPUI International Portable User Identity
IF Intermediate Frequency
LCD Liquid Crystal Display
LDO Low Drop Output
LED Light Emitting Diode

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
1. INTRODUCTION
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LGE LG Electronics
OPLL Offset Phase Locked Loop
PAM Power Amplifier Module
PCB Printed Circuit Board
PGA Programmable Gain Amplifier
PLL Phase Locked Loop
PSTN Public Switched Telephone Network
RF Radio Frequency
RLR Receiving Loudness Rating
RMS Root Mean Square
RTC Real Time Clock
SAW Surface Acoustic Wave
SIM Subscriber Identity Module
SLR Sending Loudness Rating
SRAM Static Random Access Memory
STMR Side Tone Masking Rating
TA Travel Adapter
TDD Time Division Duplex
TDMA Time Division Multiple Access
UART Universal Asynchronous Receiver/Transmitter
VCO Voltage Controlled Oscillator
VCTCXO Voltage Control Temperature Compensated Crystal Oscillator
WAP Wireless Application Protocol
8PSK 8 Phase Shift Keying

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2. GENERAL PERFORMANCE
2.1 H/W Feature
2. GENERAL PERFORMANCE
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Item Feature Comment
Standard Battery Li-ion, 900mAh
AVG TCVR Current 260mA typ @PL5
Standby Current 2 mA typ @PP9
Talk time 6 hours (GSM TX Level 10)
Standby time Over 450 hours (Paging Period:9, RSSI: -85dBm)
Charging time Under 3 hours
RX Sensitivity EGSM : -105dBm↓, DCS/PCS : -105dBm↓
TX output power EGSM : 33dBm (@PL 5)
DCS/PCS: 30dBm (@PL 0)
GPRS compatibility Class 12
SIM card type 3V Small
Display 240 x 320 pixels, 2.4 inch QVGA, 262K color, TFT
Status Indicator Soft icons, 0 ~ 9, #, *, Scroll, Send, End/PWR,
Clear AF/Camera double action, Volume Up,
Volume Down
ANT Built in antenna
EAR Phone Jack 18pin multi port Headset jack (W/O remote controller)
PC Synchronization Yes
Speech coding HR/EFR/FR/AMR
Data and Fax Yes
Vibrator Yes
Buzzer No
Voice Recoding Yes
C-Mic Yes
Receiver Yes
Travel Adapter Yes
Options Bluetooth hands-free kit, Data Kit

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2. GENERAL PERFORMANCE
2.2 Technical specification
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Item Description Specification
1Frequency Band EGSM
TX: 890 + 0.2 x n MHz
RX: 935 + 0.2 x n MHz ( n = 1 ~ 124 )
TX: 890 + 0.2 x (n-1024) MHz
RX: 935 + 0.2 x (n-1024) MHz ( n = 975 ~ 1023 )
DCS1800
TX: 1710 + ( n-511 ) x 0.2 MHz (n = 512 ~ 885)
RX: TX + 95 MHz
PCS1900
TX: 1850.2 + ( n-512 ) x 0.2 MHz (n = 512 ~ 810)
RX: TX + 80MHz
2Phase Error RMS < 5 degrees ,
Peak < 20 degrees
3Frequency Error < 0.1ppm
4Power Level EGSM
Level Power Toler. Level Power Toler.
533 dBm 2dB 13 17 dBm 3dB
631 dBm 3dB 14 15 dBm 3dB
729 dBm 3dB 15 13 dBm 3dB
827 dBm 3dB 16 11 dBm 5dB
925 dBm 3dB 17 9 dBm 5dB
10 23 dBm 3dB 18 7 dBm 5dB
11 21 dBm 3dB 19 5 dBm 5dB
12 19 dBm 3dB
DCS1800/PCS1900
Level Power Toler. Level Power Toler.
030 dBm 2dB 8 14 dBm 3dB
128 dBm 3dB 9 12 dBm 4dB
226 dBm 3dB 10 10 dBm 4dB
324 dBm 3dB 11 8 dBm 4dB
422 dBm 3dB 12 6 dBm 4dB
520 dBm 3dB 13 4 dBm 4dB
618 dBm 3dB 14 2 dBm 5dB
716 dBm 3dB 15 0 dBm 5dB

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2. GENERAL PERFORMANCE
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Item Description Specification
5Output RF Spectrum EGSM
(due to modulation) Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ 1,200 -60
1,200 ~ 1,800 -60
1,800 ~ 3,000 -63
3,000 ~ 6,000 -65
6,000 -71
DCS1800/PCS1900
Offset from Carrier (kHz). Max. dBc
100 +0.5
200 -30
250 -33
400 -60
600 ~ 1,200 -60
1,200 ~ 1,800 -60
1,800 ~ 3,000 -65
3,000 ~ 6,000 -65
6,000 -73
6Output RF Spectrum EGSM
(due to switching transient) Offset from Carrier (kHz) Max. (dBm)
400 -19
600 -21
1,200 -21
1,800 -24

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2. GENERAL PERFORMANCE
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Item Description Specification
6Output RF Spectrum DCS1800/PCS1900
(due to switching transient) Offset from Carrier (kHz). Max. (dBm)
400 -22
600 -24
1,200 -24
1,800 -27
7Spurious Emissions Conduction, Emission Status
8Bit Error Ratio EGSM
BER (Class II) < 2.439% @-102dBm
DCS1800/PCS1900
BER (Class II) < 2.439% @-100dBm
9Rx Level Report accuracy
10 SLR 8 3 dB
11 Sending Response Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 0 -12
1,000 0 -6
2,000 4 -6
3,000 4 -6
3,400 4 -9
4,000 0 -
12 RLR 2 3 dB
13 Receiving Response Frequency (Hz) Max.(dB) Min.(dB)
100 -12 -
200 0 -
300 2 -7
500 *-5
1,000 0 -5
3,000 2 -5
3,400 2 -10
4,000 2
*Mean that Adopt a straight line in between 300 Hz
and 1,000 Hz to be Max. level in the range.

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2. GENERAL PERFORMANCE
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Item Description Specification
14 STMR 13 5 dB
15 Stability Margin > 6 dB
16 Distortion dB to ARL (dB) Level Ratio (dB)
-35 17.5
-30 22.5
-20 30.7
-10 33.3
033.7
731.7
10 25.5
17 Side Tone Distortion Three stage distortion < 10%
18 System frequency 2.5ppm
(26 MHz) tolerance
19 32.768KHz tolerance 30ppm
20 Power consumption Standby
- Normal 2 mA(@PP9)
21 Talk Time EGSM/Lvl 7 (Battery Capacity 900mA):180min
EGSM/Lvl12(Battery Capacity 900mA): 320min
22 Standby Time Under conditions, at least 300 hours:
1. Brand new and full 900mAh battery
2. Full charge, no receive/send and keep GSM in idle mode.
3. Broadcast set off.
4. Signal strength display set at 3 level above.
5. Backlight of phone set off.
23 Ringer Volume At least 65 dB under below conditions:
1. Ringer set as ringer.
2. Test distance set as 50 cm
24 Charge Current Fast Charge : < 450 mA
Slow Charge: < 200 mA
25 Antenna Display Antenna Bar Number Power
7>-92 dBm ~
7 → 5-97dBm ~ -93dBm
5 → 4-100dBm ~ -98dBm
4 → 2-103dBm ~ -101dBm
2 → 1-105dBm ~ -104dBm
1 → 0<-106 dBm

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
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2. GENERAL PERFORMANCE
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Item Description Specification
26 Battery Indicator Battery Bar Number Voltage( 0.05V)
33.76V~4.2V
23.68V~3.75V
13.55V~3.65V
03.41V~
27 Low Voltage Warning 3.58V ↓0.05V (Call)
3.51V ↓0.05V (Standby)
28 Forced shut down Voltage 3.3 0.05 V
29 Battery Type Li-ion Battery or Li-Polymer Battery
Standard Voltage = 3.7 V
Battery full charge voltage = 4.2 V
Capacity: 900mAh
31 Travel Charger Switching-mode charger
Input: 100 ~ 240 V, 50/60Hz
Out put: 5.1, 0.7A

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
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2. GENERAL PERFORMANCE
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* EDGE RF Specification (Option: is not serviced for “EDGE mode”)
Item Description Specification
1RMS EVM 9%
2Peak EVM 30%
395
th Percentile EVM 15%
4Origin Offset Suppression ≥ 30dB
5Power Level EGSM
Level Power Toler. Level Power Toler.
527dBm 3dB 13 17dBm 3dB
627dBm 3dB 14 15dBm 3dB
727dBm 3dB 15 13dBm 3dB
827dBm 3dB 16 11dBm 5dB
925dBm 3dB 17 9dBm 5dB
10 23dBm 3dB 18 7dBm 5dB
11 21dBm 3dB 19 5dBm 5dB
12 19dBm 3dB
DCS1800, PCS1900
Level Power Toler. Level Power Toler.
026dBm 3dB 8 14dBm 3dB
126dBm 3dB 9 12dBm 4dB
226dBm 3dB 10 10dBm 4dB
324dBm 3dB 11 8dBm 4dB
422dBm 3dB 12 6dBm 4dB
520dBm 3dB 13 4dBm 4dB
618dBm 3dB 14 2dBm 5dB
716dBm 3dB 15 0dBm 5dB
6Output RF Spectrum EGSM
(due to modulation) Offset from carrier(kHz) Max. dBc
100 +0.5
200 -30
250 -33
400 -54
600 ~ <1,200 -60
1,200 ~ <1,800 -60
1,800 ~ <3,000 -63
3,000 ~ <6,000 -65
6,000 -71

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
2. GENERAL PERFORMANCE
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Item Description Specification
6Output RF Spectrum DCS1800, PCS1900
(due to modulation) Offset from carrier(kHz) Max. dBc
100 +0.5
200 -30
250 -33
400 -54
600 ~ <1,200 -60
1,200 ~ <1,800 -60
1,800 ~ <3,000 -63
3,000 ~ <6,000 -65
6,000 -71
7Output RF Spectrum EGSM
(due to switching transient) Offset from carrier(kHz) Max. dBm
400 -23
600 -26
1,200 -27
1,800 --30
DCS1800, PCS1900
Offset from carrier(kHz) Max. dBm
400 -23
600 -26
1,200 -27
1,800 -30

LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
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3.1 KC550 Component Block diagram
KC550 is composed with 5 different PCB part such as main PCB, Key PCB, Key FPCB, LCD FPCB
and Flash FPCB/
The functional component arrangement is mentioned below diagram.
3. TECHNICAL BRIEF
Figure 1 KC550 Functional block diagram
BB+RF
PMB8888
Memory
(1Gb NAND +
512Mb SDRAM)
Micro SD
SIM Card
Socket
Charging
ISL9221
2.4î QVGA TFT
(240x320)
2.4î QVGA TFT
(240x320)
FEM
LSHS-C085FB
PAM
TQM7M5005
Battery
900mAh
BT/FM radio
BLUCORE5-FM
Acceleration
Sensor
5M Pxl, AF
MMIC/ISP
M180
18pin
I/O
KEYPAD
: Signal , Control Connection
: RF Connection
: Power Connection
: Mechanical Connection
RF Ctrl
26MHz
Radio RX
signal
D/
4
SIM
UART
I2S
PMIC
LP3907
1.2V, 1.8V,
2.6V
Charge
Pump
BD6095
LCD B/L
Camera LDO
(1.8V, 2.8V)
Stereo
headset
TA
USB cable
TX IQ
Motor
VUSB
Audio Codec+AMP
WM8990
MIPI I/F
Backup
Battery
Headset
LCD 16bit
I/F
MMIC 16bit I/F
RCV
16pi, 3.4t
SPK
D/
16
A/
18
Flash LED
PWF4
DC/DC
Converter
BT
antenna
RX IQ
Main
antenna
Radio TX
signal

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3. TECHNICAL BRIEF
3.2 Main Chip Introduction
3.2.1 General Description
With the latest member of the S-GOLD family, S-GOLDradioTM, Infineon Technologies introduces the
world’s first single-chip solution for feature-rich mobile phones. The EDGE-capable device combines
alldigital and analog functions of the baseband, a quad-band RF transceiver, and the power
management circuitry into a single chip. With an option for memory stacking (“Package on Package”,
JEDEC compliant) the key functions of a mobile phone are now combined into a single device,
providing all the benefits that come from a maximum level of integration. Full software re-use from the
proven Infineon EDGE platform, MP-ELite, enables fast time-to-market using a comprehensive
development kit available to all customers today.
S-GOLDradioTM is tailored to fit the requirements of EDGE-enabled feature phones with a standard
set of multimedia applications such as:
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Figure 2 Application View of the S-GOLDradioTM Block Diagram

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3. TECHNICAL BRIEF
• Still picture imaging up to 2 MPixel
• MPEG4 video encode/decode
• Video streaming
• MP3 playback
• Java applications.
This single chip solution allows for very small form factor phones with a high degree of power
efficiency.
Its low cost structure makes multimedia feature-enhanced EDGE phones very affordable for price-
sensitive market segments. S-GOLDradioTM°Øs small footprint, competitive cost position, and low
power consumption also makes it the perfect fit for EDGE-capable data cards.
S-GOLDradioTM’s baseband processing is powered by an ARM926EJ-S CPU and a TEAKLite® DSP
core.
The ARM926EJ-S is a powerful standard controller and particularly suited for wireless systems. It is
supported by a wide range of tools and application SW.
The TEAKLite® is an established DSP core for wireless applications with approved firmware for GSM
signalprocessing. The Infineon Technologies DSP firmware and software modules for FR, HR, EFR
and AMR-NB vocoding and channel encoding allow a short time to market. Additionally, S-
GOLDradioTM supports multislot operation modes:
HSCSD (up to class 10), GPRS for high speed data applications (up to class 12) and EGPRS (up to
class 12) without additional external hardware.
A wide choice of communication interfaces allows complex data and multimedia system designs.
Furthermore, S-GOLDradioTM contains its own Power Supply and Battery Management. Its design is
optimized forall mobile platform needs (such as graphic displays with backlights) and internal needs
(analog components, loudspeaker, USB, etc.). S-GOLDradioTM is driven directly from re-chargeable
batteries such as Li-Ion or Li-Polymer batteries. S-GOLDradioTM Power Management provides
different supply voltages by using highly efficient DCDC converters, DCDC boost converters and
linear, low-dropout regulators (LDOs). In addition, it supports battery charging, generates stand-by
voltages and supports different low power modes.
The S-GOLDradioTM RF capability features a quad-band transceiver for
EGSM/GSM900/GSM1800/GSM1900, and it is designed for voice and data transfer applications. Its
architecture consists of a direct conversion receiver and a quad-band polar transmitter for
GSM/EDGE.
Accurate output power setting is ensured by an integrated power control loop, which supports linear
and non-linear power amplifiers. The entirely integrated quad-band RF oscillator and Sigma-Delta
synthesizer give the S-GOLDradioTM HSCSD and GPRS/EDGE capabilities.
Figure 2 shows a typical application example: The S-GOLDradioTM as a single chip solution acting as
a multifunctional engine in a complete mobile phone platform.
LGE Internal Use Only Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes