LG GM730 Service Manual

Service Manual Model : GM730

Internal Use Only

Service Manual

GM730

Date: May 2009 / Issue 1.0

Table Of Contents

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 ......................................................9

2.4 Current Consumption ................................................13

2.5 RSSI BAR ..................................................................14

2.6 Battery BAR ..............................................................14

3. TECHNICAL BRIEF .........................................15

3.1 GENERAL DESCRIPTION .............................................15

3.2 GSM MODE ...............................................................16

3.3 UMTS MODE .............................................................20

3.4 GPS MODE ...............................................................23

3.5 LO GENERATION and DISTRIBUTION CIRCUIT ..............23

3.6 OFF-CHIP RF COMPONENTS ......................................24

3.7 Main Features ...........................................................28

3.8 Digital Baseband(DBB/MSM7200A) ............................33

3.9 Hardware Architecture ...............................................34

3.10 Subsystem(MSM7200A) ..........................................36

3.11 Power Block ............................................................39

3.12 External memory interface .......................................44

3.13 H/W Sub System .....................................................46

3.14 Audio and sound .....................................................55

3.15 Camera interface .....................................................62

3.16 Proximity Sensor .....................................................69

3.17 Luminance Sensor ...................................................70

3.18 Motion Sensor .........................................................71

4. TROUBLE SHOOTING ..................................... 72

4.1 RF Component ..........................................................72

4.2 SIGNAL PATH ............................................................74

4.3 Checking TCXO Block ................................................78

4.4 Checking Front End Module(FEM) Block ......................80

4.5 Checking WCDMA Block ............................................83

4.6 Checking GSM Block .................................................95

4.7 Power ON Troubleshooting .......................................102

4.8 Charger Troubleshooting ..........................................104

4.9 USB trouble .............................................................107

4.10 Audio trouble .........................................................109

4. 11 5M Camera trouble ...............................................119

4.12 VGA Camera trouble ..............................................122

4.13 Main LCD trouble ..................................................125

4.14 SIM Detect Troubleshooting ....................................127

4.15 Keypad Backlight Troubleshooting ...........................129

4.16 LINEAR MOTOR .....................................................130

4.17 Proximity Sensor on/off trouble ...............................131

4.18 Luminance Sensor on/off trouble ............................133

4.19 Motion Sensor on/off trouble ..................................135

5. Downloading .............................................. 137

5.1 Introduction .............................................................137

5.2 Downloading Procedure ...........................................138

6. BLOCK DIAGRAM ........................................ 147

7. CIRCUIT DIAGRAM ...................................... 157

8. BGA Pin Map .............................................. 165

9. PCB LAYOUT ...............................................173

10. Calibration & RF Auto Test Program

(Tachyon) .................................................. 177

10.1 Confi guration of Tachyon .......................................177

10.2 How to use Tachyon ...............................................179

11. Test Mode ................................................. 182

12. EXPLODED VIEW & REPLACEMENT

PART LIST ................................................ 191

12.1 EXPLODED VIEW ...................................................191

12.2 Replacement Parts ................................................193

12.3 Accessory ............................................................. 219

Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes

- 3 -

LGE Internal Use Only

LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.

- 4 -

Only for training and service purposes

1. INTRODUCTION

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.

1. INTRODUCTION

Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes

- 5 -

LGE Internal Use Only

1. INTRODUCTION

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.

LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.

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Only for training and service purposes

2. PERFORMANCE

2.1 System Overview

7. LCD

8. Main Camera
(3M)

Type /

Spec.

Bar Type1. Phone Type

109.8 x 56.5 x 11.9 (mm)2. Size

106g3. Weight

1000mAh (Li-Ion)4. Power

MSM7200A, RTR6285, PM75405. MSM Chipset

4Gb(Flash) / 2Gb(SDRAM) /User Memory : 100 MB(TBD)6. Memory

Size

Color

Display Type

NTSC

Contrast Ratio

Type

Resolution

Digital Zoom

ling Down

Video

2. PERFORMANCE

3 inch

400 x 240Dot

262,000

a-Si TFT, Trans missive

Min. 65%, Typ. 70%

Typ. 400:1

0.162mmPixel Pitch

CMOS image sensor

2592(H) X 1944(V) pixels. WQVGA

30 fps at Preview modeFrame Rate

Progressive, <=X2

SXGA, VGA, QVGA, CIF, QCIFImage Sca

400x240 / 176x144,

9. Audi

o

10. Bluetooth

11. WLAN

Throughput

Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes

72poly, SW MIDI1) MIDI

18x12 oval type speaker2) Mono

Speaker/Receiver 3) Receiver

1m

IEEE 802.11b/

4Mbps

50 ~ 200m

- 7 -

g

LGE Internal Use Only

2. PERFORMANCE

2.2 Usable environment

1) Environment

2) Environment (Accessory)

Item Specification

Voltage 3.7 (Typ), 4.2 (Max)V

Operation Temp -20 ~ +60°C

Storage Temp -30 ~ +85°C

Humidity 65 % (Max)

Reference Spec.

TA Power AC 110 ~ 240V, 60Hz

LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.

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Only for training and service purposes

2. PERFORMANCE

2.3 Radio Performance

1) Transmitter - GSM Mode

SpecificationItem

Phase Error

Frequency Error

EMC(Radiated Spurious Emission
Disturbance)

Transmitter Output power and Burst
Timing

Spectrum due to modulation out to less
than 1800kHz offset

Spectrum due to modulation out to larger
than 1800kHz offset to the edge of the
transmit band

Spectrum due to switching transient

RMS : 5
Peak : 20 

GSM : 0.1 ppm
DCS/PCS : 0.1 ppm

GSM/DCS : < -28dBm

GSM : 5dBm – 33dBm  3dB
DCS/PCS : 0dBm – 30dBm  3dB

<3.69usBurst Timing
200kHz : -36dBm

600kHz : -51dBm/-56dBm

GSM :
1800-3000kHz :< -63dBc(-46dBm)
3000kHz-6000kHz : <-65dBc(-46dBm)
6000kHz < : < -71dBc(-46dBm)
DCS :
1800-3000kHz :< -65dBc(-51dBm)

6000kHz < : < -73dBc(-51dBm)

400kHz : -19dBm/-22dBm(5/0), -23dBm
600kHz : -21dBm/-24dBm(5/0), -26dBm

Class II(RBER) : -105dBm(2.439%)Reference Sensitivity – TCH/FS

Intermodulation rejection – Speech
channels

AM Suppression

-GSM : -31dBm - DCS : -29dBm

Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes

0.012(-15 - -40dBm)Usable receiver input level range

 800kHz,  1600kHz
: -98dBm/-96dBm (2.439%)

-98dBm/-96dBm (2.439%)

 0.5TTiming Advance

- 9 -

LGE Internal Use Only

2. PERFORMANCE

2) Transmitter - WCDMA Mode

SpecificationItem

Transmit Frequency

Maximum Output
Power

Open Loop Power
Control

Minimum Transmit
Power

Occupied Bandwidth
Adjacent Channel

Leakage
Power Ratio (ACLR)

Spurious Emissions
|f-f

| > 12.5 MHz

c

WCDMA850 : 824 MHz ~ 849 MHz
WCDMA900 : 880 MHz ~ 915MHz
WCDMA1900 : 1850 ~1910 MHz
WCDMA2100 : 1920 MHz ~ 1980 MHz

+24 dBm / 3.84 MHz, +1 / -3 dB

within 0.1 PPMFrequency Error
Normal Conditions : within 9 dB,

Extreme Conditions : within 12 dB
< -50 dBm /3.84 MHz

< 5 MHz at 3.84 Mcps (99% of power)
> 33 dB @ 5 MHz,

> 43 dB @ 10 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

Peak Code Domain
Error

LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.

< -31 dBc @ 5 MHz & < -41 dBc @ 10 MHz
when Interference CW Signal Level = -40 dBc

< 17.5 %, when Pout ≥ -20 dBmError Vector Magnit u de
< -15 dB at Pout t -20 dBm

- 10 -

Only for training and service purposes

2. PERFORMANCE

3) Receiver - WCDMA Mode

SpecificationItem

Receive Frequency

Adjacent Channel
Selectivity (ACS)

Blocking Characteristic

Intermodulation

Spurious Emissions

WCDMA850 : 849 MHz ~ 894 MHz
WCDMA900 : 925MHz ~ 960 MHz
WCDMA1900 : 1930 ~1990 MHz

WCDMA2100 : 2110 ~ 2170 MHz
BER < 0.001 when Î
BER < 0.001 when Î
ACS > 33 dB where BER < 0.001 when Î

& I

= –52 dBm / 3.84 MHz @ 5 MHz

oac

BER < 0.001 when Î
& I
or I

= -56 dBm / 3.84 MHz @ Fuw(offset) = 10 MHz

blocking

= -44 dBm / 3.84 MHz @ Fuw(offset) = 15 MHz

blocking

BER < 0.001 when Î

BER < 0.001 when Î
& I

= -46 dBm @ F

ouw1

= -46 dBm / 3.84 MHz @ F

& I

ouw2

= -106.7 dBm / 3.84 MHzReference Sensitivity Level

or

= -25 dBm / 3.84 MHz Maximum Input Level

or

= -92.7 dBm / 3.84 MHz

or

= -103.7 dBm / 3.84 MHz

or

= -103.7 dBm / 3.84 MHz & I

or

= -103.7 dBm / 3.84 MHz

or

(offset) = 10 MHz

uw1

(offset) = 20 MHz

uw2

< -57 dBm / 100 kHz BW @ 9 kHz ≤ f < 1 GHz
< -47 dBm / 1 MHz BW @ 1 GHz ≤ f ≤ 12.75 GHz

blocking

= -44 dBmSpurious Response

Inner Loop Power Control

In Uplink

Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes

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

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LGE Internal Use Only

2. PERFORMANCE

4) Transmitter - HSDPA Mode

SpecificationItem

Transmit Frequency

Maximum Output
Power

HS-DPCCH

824 MHz ~ 849 MHz
880 MHz ~ 915 MHz
1850MHz ~ 1910 MHz
1920 MHz ~ 1980 MHz

Sub-Test
1=1/15, 2=12/15 21~25dBm / 3.84 MHz
3=13/15 4=15/8 20~25dBm / 3.84 MHz
5=15/7 6=15/0 19~25dBm / 3.84 MHz

Sub-

test in

table

C.10.1.

4

5

Sub-Test : 1=1/15, 2=12/15, 3=13/15, 4=15/8, 5=15/7, 6=15/0

Power

step

Power step slot boundary

Power

step size,

P [dB]

Transmitter

power step

tolerance

[dB]

+/- 2.36Start of Ack/Nack1
+/- 0.61Start of CQI2
+/- 0.60Middle of CQI3
+/- 2.35End of CQI4

Frequency offset from

carrier △f

Spectrum Emission
Mask

Adjacent Channel
Leakage
Power Ratio (ACLR)

LGE Internal Use Only Copyright © 2009 LG Electronics. Inc. All right reserved.

Sub-Test : 1=1/15, 2=12/15, 3=13/15, 4=15/8, 5=15/7, 6=15/0
> 33 dB @ 5 MHz

> 43 dB @ 10 MHz
3GPP Not CompleteError Vector Magnit u de

- 12 -

Minimum requirement

Only for training and service purposes

Measurement

Bandwidth

30 kHz-35-15×(△f-2.5)dBc2.5 ~ 3.5 MHz

1 MHz-35-1×(△f-3.5)dBc3.5 ~ 7.5 MHz
1 MHz-35-10×(△f-7.5)dBc7.5 ~ 8.5 MHz
1 MHz-49dBc8.5 ~ 12.5 MHz

5)Receiver - HSDPA Mode

2.4 Current Consumption

1) Current Consumption

(Stand by and Voice Call Test Condition : Bluetooth off, LCD backlight off,Neighbor Cell off) (VT Test
Condition : Speaker off, LCD backlight On)

No Item Specification

1 Receive Frequency 849 MHz ~ 894 MHz

1930 MHz ~1990 MHz

2110 ~ 2170 MHz

2 Maximum Input Level Sub-Test : 1=1/15, 2=12/15, 3=13/15, 4=15/8, 5=15/7, 6=15/0

(BLER or R), 16QAM Only BLER < 10% or R >= 700kbps

Stand by Voice Call VT

Bluetooth Bluetooth

Off Connected

WCDMA

Under 3.00 mA Under 4.50 mA Under 250 mA N/A

(DRX=1.28) (DRX=1.28) (TX=12dBm low)

GSM Under 3.00 mA Under 4.50 mA Under 350 mA

Paging=5 period Paging=5 period (TX Power Level 5)

Receive Frequency

Maximum Input Level
(BLER or R), 16QAM Only

2. PERFORMANCE

SpecificationItem

849 MHz ~ 894 MHz
925 MHz ~ 960 MHz
1930 MHz ~1990 MHz
2110 ~ 2170 MHz

Sub-Test : 1=1/15, 2=12/15, 3=13/15, 4=15/8, 5=15/7, 6=15/0

BLER < 10% or R >= 700kbps













































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Only for training and service purposes

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LGE Internal Use Only

2. PERFORMANCE

2.5 RSSI BAR

2.6 Battery BAR

Indication Standby

Bar 4 → 3 72%

Bar 3 → 2 47%

Bar 2 → 1 25%

Bar 1 → 05%

Low Battery Alarm 15%

Critical Low Battery Alarm 5%

POWER OFF 0%

Level Change WCDMA GSM

BAR 4 → 3-82 ± 2 dBm -91 ± 2 dBm

BAR 3 → 2-92 ± 2 dBm -96 ± 2 dBm

BAR 2 → 1 -102 ± 2 dBm -101 ± 2 dBm

BAR 1 → 0 -112 ± 2 dBm -106 ± 2 dBm

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Only for training and service purposes

3. TECHNICAL BRIEF



3. TECHNICAL BRIEF

3.1. GENERAL DESCRIPTION

The GM730 supports UMTS-900(Band VIII), UMTS-1900(Band II), UMTS-2100(Band I), GSM-850, GSM-900,
GSM-1800, and GSM-1900 based GSM/GPRS/EDGE/UMTS. All receivers and the UMTS transmitter use the
radioOne1Zero-IF architecture to eliminate intermediate frequencies, directly converting signals between RF
and baseband. The quad-band GSM transmitters use a baseband-to-IF up-conversion followed by an offset
phase-locked loop that translates the GMSK-modulated or 8-PSK-modulated signal to RF.

TCXO

SBDT

RF_ON

TX_IQ

PRX_IQ

DRX_IQ

DAC_IREF

VCTCXO

19.2MHz

VCONT

GPS_LNA_EN

WCDMA_900_ON
WCDMA_1900_ON
WCDMA_2100_ON

TCXO_EN
TRK_LO_ADJ
TCXO

PMIC_SSBI
PA_POWER_CTL

PA_RANGE0

SSBDT_RTR
TX_ON

MSM7200A

GPIO58
GPIO22

GPIO110
PA_ON0

TX_IQ

PRX_IQ

DRX_IQ

DAC_IREF

ANT_SEL0/1/2/3

VBATT

VAPC

FRONT

END

MODULE

SKY77521

LB_RF_IN

HB_RF_IN

CTRL0/1/2/3

GSM_PA_RAMP

WCDMA2100

DIVERSITY

RX4
RX3

RX2
RX1

W900

Duplexer

W2100

Duplexer

W1900

Duplexer

+VPWR

49.9R

Coupler

O

O

T

T

Coupler

T

T
O

O

Coupler

O

O

T

T

RX SAW

FILTER

RX SAW

FILTER

RX SAW

FILTER

RX SAW

FILTER

RX SAW

FILTER

I

I
C

C

C

C

I

I

I

I
C

C

G850/900

DCS/PCS

LNA

WCDMA_900_ON

WCDMA_2100_ON

VMODE1

WCDMA

Dual PAM

VMODE2

VMODE2

W1900

PAM

VMODE1

WCDMA_1900_ON

GSM850
EGSM900
DCS1800
PCS1900

GPS_LNA_EN

RX SAW

FILTER

WCDMA900 TX

TX SAW

FILTER

WCDMA2100 TX

TX SAW

FILTER

WCDMA1900 TX

TX SAW

FILTER

RX SAW

FILTER

PM7540

SBDT_SSBI

GPS_IN
WB_MX_INP

WB_MX_INM
WPRXSE2_OUT

WPRXSE2

WPRXLBP
WPRXLBN

LB_RF_OUT2

HB_RF_OUT3

HB_RF_OUT2

PDET_IN
WPRXHBP

WPRXHBN

WDRXHB2

LB_RF_OUT1
HB_RF_OUT1
GCELL_INP

GCELL_INP
GCELL_INN

GCELL_INN
EGSM_INP

EGSM_INP
EGSM_INN

EGSM_INN
DCS_INP

DCS_INP
DCS_INN

DCS_INN
GPCS_INP

GPCS_INP

GPCS_INP
GPCS_INN

GPCS_INN

GPCS_INN

PMIC_TCXO

RTR6285

[Figure 1-1] Block diagram of RF part

A generic, high-level functional block diagram of GM730 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 SKY77521 (FEM, Front End Module + GSM PAM). The UMTS receive paths each
include an LNA, an RF band-pass filter, and a downconverter that translate the signal directly from RF-to­baseband using radioOne ZIF techniques. The RFIC’s RX analog baseband outputs, for the receive chains,
connect to the MSM IC. The UMTS and GSM RX baseband outputs share the same inputs to the MSM IC.

For the transmit chains, the RTR6285 IC directly translates the TX baseband signals (from
the MSM device) to an RF signal using an internal LO generated by integrated on-chip PLL
and VCO. The RTR6285 IC outputs deliver fairly high-level RF signals that are first filtered by
TX SAWs and then amplified by their respective UMTS PAs.

1

QUALCOMM’s branded chipset that implements a Zero-IF radio architecture.

Copyright © 2009 LG Electronics. Inc. All right reserved.

- 15 -

Only for training and service purposes

LGE Internal Use Only

3. TECHNICAL BRIEF





In the GSM receive path, the received RF signals are applied through their band-pass filters and down­converted directly to baseband in the RTR6285 transceiver IC. These baseband outputs are shared with the
UMTS receiver and routed to the MSM IC for further signal processing.
The GSM/EDGE transmit path employs one stage of up-conversion and, in order to improve efficiency, is
divided into phase and amplitude components to produce an open-loop Polar topology:

1. The on-chip quadrature up-converter translates the GMSK-modulated signal or 8-PSK modulated signal, to
a constant envelope phase signal at RF;

2. The amplitude-modulated (AM) component is applied to the ramping control pin of Polar power amplifier
from a DAC within the MSM

GM730 power supply voltages are managed and regulated by the PM7540 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 user-defined 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.

3.2. GSM MODE

3.2.1 GSM RECEIVER

The GSM-850, GSM-900, GSM-1800, and GSM-1900 receiver inputs of RTR6285 are connected to the
transceiver front-end circuits(switch module) through saw filters. GSM-850, GSM-900, GSM-1800, and GSM­1900 receiver inputs use differential configurations to improve common-mode rejection and second-order
non-linearity performance as shown in Figure 1-2. The balance between the complementary signals is critical
and must be maintained from the RF filter outputs all the way into the IC pins

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- 16 -

Only for training and service purposes

3. TECHNICAL BRIEF





[Figure 1-2] GSM Receiver Inputs Topologies

Since GSM-850, GSM-900, GSM-1800, and GSM-1900 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 GSM-850, GSM-900, GSM-1800, and GSM-1900
receive signals are routed to the RTR6285 through saw filters and matching networks that transform single­ended 50-Ω sources to differential impedances optimized for gain and noise figure. The RTR input uses a 
differential configuration to improve second-order inter-modulation and common mode rejection
performance. The RTR6285 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 or 8-PSK processing. These filter circuits include DC
offset corrections. The filter outputs are buffered and passed on to the MSM7200A IC for further processing as
shown in Figure 1-3.

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[Figure 1-3] RTR6285 RX feature

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3.2.2 GSM TRANSMITTER

The RTR6285 transmitter outputs(HB_RF_OUT1 and LB_RF_OUT1) include on-chip output matching
inductors. 50ohm output impedance is achieved by adding a series capacitor at the output pins. The
capacitor value may be optimized for specific applications and PCB characteristics based on pass-band
symmetry about the band center frequency as shown in Figure 1-3.

[Figure 1-4] GSM Transmitter Outputs Topologies

The RTR6285 IC is able to support GSM850/GSM 900 and GSM 1800/1900 mode transmitting. This design
guideline shows a quad-band GSM application. Both high-band and low band outputs are followed by
resistive pads to ensure that the load presented to the outputs remains close to 50ohm.

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3.3. UMTS MODE

3.3.1 UMTS RECEIVER

The UMTS duplexer receiver output is routed to LNA circuits within the RTR6285 device as shown in Figure 1-

5. The UMTS RX input is provided with an on-chip LNA that amplifies the signal before a second stage filter
that provides differential downconverter as shown in Figure 1-5. This second stage input is configured
differentially to optimize second-order intermodulation and common mode rejection performance. The gain
of the UMTS front end amplifier and the UMTS second stage differential amplifier are adjustable, under MSM
control, to extend the dynamic range of the receivers. The second stage UMTS RX amplifiers drive the RF
ports of the quadrature RF-to-baseband downconverters. The downconverted UMTS RX baseband outputs
are routed to lowpass filters having passband and stopband characteristics suitable for UMTS RX processing.
These filter circuits allow DC offset corrections, and their differential outputs are buffered to interface shared
with GSM RX to the MSM IC. The UMTS baseband outputs are turned off when the RTR6285 is
downconverting GSM signals and on when the UMTS is operating.

[Figure 1-5] UMTS Receiver Inputs Topologies

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3.3.2 UMTS TRANSMITTER

The UMTS TX path begins with differential baseband signals (I and Q) from the MSM device.
These analog input signals are amplified, filtered, and applied to the quadrature up-converter mixers. The up­converter output is amplified by multiple variable gain stages that provide transmit AGC control. The AGC
output is filtered and applied to the driver amplifier; this output stage includes an integrated matching
inductor that simplifies the external matching network to a single series capacitor to achieve the desired 50­Ω interface.

The RTR6285 UMTS output is routed to its power amplifier through a bandpass filter, and delivers fairly high­level signals that are filtered and applied to the PA. Transmit power is delivered from the duplexer to the
antenna through the switch module.
The transceiver LO synthesizer is contained within the RTR6285 IC with the exception of the off-chip loop
filter components and the VC-TCXO. This provides a simplified design for multimode applications. The PLL
circuits include a reference divider, phase detector, charge pump, feedback divider, and digital logic
generator.

UMTS TX Using only PLL1, the LO generation and distribution circuits create the necessary LO signals for nine
different frequency converters. The UMTS transmitter also employs the ZIF architecture to translate the signal
directly from baseband to RF. This requires FLO to equal FRF, and the RTR6285 IC design achieves this without
allowing FVCO to equal FRF.
The RTR6285 IC is able to support UMTS 2100/1900/1800/1700/900 and 850 mode transmitting. This design
guideline shows UMTS 2100, UMTS1900 and UMTS850 applications.

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[Figure 1.6] RTR6285 IC Functional Block Diagram

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3.4. GPS MODE

3. TECHNICAL BRIEF

3.4.1 GPS RECEIVER

The GPS receiver input employs a single-ended connection realized by this pin. The GPS input is routed from
the GPS antenna switch, through a band-pass filter and then an impedance transformer circuit that optimally
matches the impedance looking into the GPS LNA. The impedance transformer circuit topology is shown in
Figure 1-7.

[Figure 1.7] GPS Input Network Topology

3.5. LO GENERATION and DISTRIBUTION CIRCUIT

The integrated LO generation and distribution circuits are driven by internal VCOs to support various modes
to yield highly flexible quadrature LO outputs that drive all GSM/EDGE, UMTS band and GPS upconverters
and downconverters; with the help of these LO generation and distribution circuits, true zero-IF architecture
is employed in all GSM and UMTS band receivers and transmitters to translate the signal directly from RF-to­baseband and from baseband-to-RF. Two fully functional fraction-N synthesizers, including VCOs and loop
filters, are integrated within the RTR6285 IC. In addition, the RTR6285 has a third synthesizer used for GPS
operation. The first synthesizer (PLL1) in the RTR6285 creates the transceiver Los that support the UMTS
transmitter, and all four GSM band receivers and transmitters including: GSM850, GSM900, GSM1800, and
GSM1900. The second synthesizer (PLL2) in the RTR6285 IC provides the LO for the UMTS primary receiver. For
the RTR6285 IC only, the second synthesizer also provides the LO for the secondary UMTS receiver. The third
synthesizer (PLL3), only in the RTR6285 IC, provides the LO for the GPS receiver. An external TCXO input signal
is required to provide the synthesizer frequency reference to which the PLL is phase and frequency locked.
The RTR6285 ICs integrate most of the PLL loop filter components on-chip except for three off-chip loop
filter-series capacitors, which significantly reduces off-chip component requirement. With the integrated
fractional-N PLL synthesizers, the RTR6285 ICs have the advantage of more flexible loop bandwidth control,
fast lock time, and low-integrated phase error.

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3.6. OFF-CHIP RF COMPONENTS

3.6.1 ALM-1412(U108:GPS LNA)

The ALM-1412 is an LNA module, with integrated filter, designed for GPS band applications at 1.575GHz. The
LNA uses AVAGO Technologies’ proprietary GaAs Enhancement-mode pHEMT process to achieve high gain
with very low noise figure and high linearity Noise figure distribution is very tightly controlled. A CMOS­compatible shutdown pin is included either for turning the LNA on/off, or for current adjustment. The
integrated filter utilizes an Avago Technologies’ leading edge FBAR filter for exceptional rejection at Cell/PCS
Band frequencies. The ALM-1412 is useable down to 1V operation. It achieves low noise figure, high gain and
linearity even at 1V, making it suitable for use in critical low-power GPS applications or during low-battery
situations.

3.6.2 SKY77521(U101:FEM + GSM Quad-Band PAM)

SKY77521 is transmit and receive Front End Module(FEM) designed in a very low profile
(1mm), compact form factor for quad-band cellular handsets comprising GSM850/900,
DCS1800, and PCS1900 operation – a complete transmit VCO-to-Antenna and Antenna-to­receive SAW filter solution. The FEM also supports Class 12 General Packet Radio Service
(GPRS) multi-slot operation and EDGE Polar Modulation. WCDMA switch-through support is
provided by three dedicated high-linearity ports.

[Table 1] Antenna Switch Module Logic

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[Figure 1.8] SKY77521 Functional Block Diagram.

3.6.3 W-CDMA Dual-Band POWER AMPLIFIER (U104: AWT6224R)

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[Figure 1.9] AWT6224R Functional Block Diagram.

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3.6.4 W-CDMA 1900 POWER AMPLIFIER (U107: AWT6278R)

.

[Figure 1.10] AWT6278R Functional Block Diagram.

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3.7 Main Features

1. LG GM730 Main Features

- Bar Type Simple & Stylish design

- UMTS 2100 + UMTS1900 + UMTS900+

GSM 900 + DCS 1800 + PCS 1900 + GSM850 based GSM/GPRS/EDGE/UMTS

- HSDPA 3.6Mbps

- 3.0” WQVGA LCD (262K TFT)

- Touch Sensitive User Interface

- 5M AF Camera

- Stereo Headset & Speaker phone

- 72 Poly Sound

- MP3/AAC/AMR/MIDI/3GP/SMAF decoder and play

- MPEG4 encoder/decoder and play/save

- JPEG en/decoder

- Supports Bluetooth and HS-USB

- Supports WLAN

- Internal User Memory over 128MB

- 1000 mAh (Li-Ion Polymer)

- Windows MobileTM6.1 Professional

- Microsoft Office Mobile

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2. GM730 Main Component

WLAN,BT,FM

BB/MEM/Logic

PMIC

3. TECHNICAL BRIEF

Logic

RF

RF & GPS

Logic

VGA

Camera &

Sensor

Volume

SIDEKEY

Main board, Top

MIC

Power &

Reset

SIDEKEY

Camera

SIDEKEY

Main board, Bottom

5M Camera

Optical Joystick

Logic

USIM

Sub board, Top

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Sub board, Bottom

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RF

S501

FL106

FL107

FL111

FL108

U107

U106

U105

U104

U108

FL110

U102

FL104

FL103

FL101

FL100

FL109

FL105

U101

FL112

SW100

U103

DescriptionReferenceDescriptionReference

FL107RTR6285(Transceiver)U102

FL105FEM & GSM PAMU101

FL112WCDMA Dual (I,VIII) PAMU104

FL109WCDMA (II) PAMU107

FL106WCDMA (II) TX SAW FilterFL111

U108WCDMA (I) TX SAW FilterFL108

FL110WCDMA (II) CouplerU106

FL100EGSM Rx SAW FilterFL101

FL104WCDMA (I) CouplerU105

FL103WCDMA (VIII) CouplerU103

WCDMA (VIII) TX SAW

WCDMA (VIII) Duplexer

WCDMA (II) Duplexer

WCDMA (I) Duplexer

WCDMA (I) RX SAW Filter

GPS LNA

GPS SAW Filter

GSM850 Rx SAW Filter

PCS Rx SAW Filter

DCS Rx SAW Filter

Micro-SD SocketS501Test ConnectorSW101

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Logic / BB / MEM / Audio/WLAN

3. TECHNICAL BRIEF

X501

X201

U503

U405

U203

U501

U502

CN402

U402
U401

CN401

U302

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- 31 -

DescriptionRef.DescriptionRef.

Battery ConnectorCN402TCXO (9.2MHz)X201

Audio SubsystemU501TCXO (26MHz)X501

Audio SubsystemU502Wi-Fi &BT & FM ModuleU503

USB TransceiverU402PMIC, PM7540U405

Over-voltage ProtectionU401MCU, MSM7200AU203

Micro USB 5Pin Con.CN401Memory, MCPU302

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