LG L-06A Service Manual

Service Manual Model : L-06A

Internal Use Only

Service Manual

L-06A

Date: July, 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 wireless characteristic .................................................9

2.4 Current consumption .................................................15

2.5 RSSI (Call (W2100 0dBm /EGSM Power level 19) :

Cell Power) ...............................................................15

2.6 Battery Bar ................................................................16

2.7 Sound pressure Level ................................................17

2.8 SAR characteristic .....................................................18

3. TECHNICAL BRIEF .........................................19

3.1 General Description ...................................................19

3.2 GSM Mode ................................................................22

3.3 UMTS Mode ..............................................................26

3.4 LO Phase-locked Loop ...............................................31

3.5 Off-chip RF Components ............................................32

3.6 Digital Baseband(DBB/MSM7200A) ............................47

3.7 Modem subsystem ....................................................50

3.8 Power Block ..............................................................63

3.9 Memory interface ......................................................73

3.10 H/W Sub System .....................................................75

3.11 Main Features .........................................................93

4. TROUBLE SHOOTING ................................... 103

4.1 Checking VCXO Block ..............................................103

4.2 Checking Ant. SW Module Block ...............................105

4.3 Checking UMTS Block ..............................................107

4.4 Checking GSM Block ...............................................116

4.5 Power ON Troubleshooting .......................................120

4.6 Charger Troubleshooting ..........................................123

4.7 USB Troubleshooting ................................................125

4.8 SIM Detect Troubleshooting ......................................128

4.9 Keypad Backlight Troubleshooting .............................135

4.10 Folder Close / Open Troubleshooting .......................136

4.11 Swivel Close / Open Troubleshooting .......................137

4.12 Main LCD Troubleshooting......................................138

4.13 Receiver Path ........................................................139

4.14 Headset path.........................................................141

4.15 Speaker phone path ..............................................142

4.16 Main microphone ..................................................144

4.17 Headset microphone ..............................................146

4.18 Vibrator .................................................................148

4.19 1-seg ...................................................................150

4.20 3AXIS Sensor ........................................................152

4.21 Touch Sensor ........................................................153

4.22 SD card operation..................................................155

4.23 Light Sensor Operation ..........................................158

4.24 FeliCa ...................................................................159

5. Downloading .............................................. 161

5.1 Introduction .............................................................161

5.2 Downloading Procedure ...........................................162

5.3 Troubleshooting Download Errors ..............................177

5.4 Caution ...................................................................184

6. BLOCK DIAGRAM ........................................ 185

6.1 GSM & UMTS RF Block ............................................185

6.2 RF Component ........................................................186

7. CIRCUIT DIAGRAM ...................................... 193

8. BGA Pin Map ..............................................203

9. PCB LAYOUT ...............................................213

10. Calibration & RF Auto Test Program

(Hot Kimchi) ............................................. 221

10.1 Conﬁ guration of HOT KIMCHI .................................221

10.2 How to use HOT KIMCHI.........................................223

11. EXPLODED VIEW & REPLACEMENT

PART LIST ................................................225

11.1 EXPLODED VIEW ...................................................225

11.2 Replacement Parts ................................................227

11.3 Accessory ............................................................. 262

- 3 -

LGE Internal Use Only

- 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

- 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.

- 6 -

Only for training and service purposes

2. PERFORMANCE

2.1 System Overview

2. PERFORMANCE

SpecificationItem

External form

Call time

Wait time

WCDMA2100,800/GSM900/DCS1800/PCS1900 Swivel type Dual mode mobile phone

110X52X15.4 [mmXmmXmm]Size

about 131g (Battery included)Weight

3.7V, 900mAh Li-IonPower

Over 180 min. (WCDMA, Tx=10 dBm, Voice) 260 mA Over 140 min (GSM900, Tx= greatest output, Voice) 330 mA

Over 300 hrs (WCDMA only mode, DRX = 2.56s) (under 3.0 mA) Over 250 hrs (GSM, Paging period = 5) (under 3.5 mA)

In 3 hours ( 0

IntennaAntenna

3.0"(480x800 Dot), 262K TFT Color LCDMain LCD

White LED Back LightMain LCD BL

Yes (10 pie coin type)Vibrator

Yes LED Indicator

Yes (SMD type)C-Mic

Yes (18X10)Receiver

~ 40O )Charging time

Yes (18X10)Loud Speaker

Yes (10 pin Japan standard)Ear phone jack

Yes (3.0V/1.8V)SIM Socket

Push Type Side Key(+,-)Volume Key

Push TypeVoice Key

ARIB Type A (10 pin + RF coaxial)I/O Connector

- 7 -

LGE Internal Use Only

2. PERFORMANCE

2.2 Usable environment

1) Phone using environment

Item

Using Voltage V3.7 (Typ) ( Shut Down: 3.28)

Using Temp.

Store Temp.

humidity 40 ~ 85 %

2) Using environment(Accessory)

Item Unit

Input power

* TA support FOMA common adapter.

UnitSpec.

-20 ~ + 60

-30 ~ + 85 ℃

Spec.

Using power 100 220 240

MaxTyp.Min

℃

Vac

- 8 -

Only for training and service purposes

2. PERFORMANCE

2.3 wireless characteristic

wireless characteristic follows GSM Approval examination Specification(ETSI EN 300 607 11.10)

1) Frequency characteristic of transmission part - GSM Mode

3 Phase Error

Item

Conducted MS

Spurious Emission -39dBm

Radiated -36dBm

Spurious Emission

allocated

Channel

Idle Mode

MS allocated

Channel

Idle Mode

Frequency Error

100k ~ 1GHz -39dBm

1G ~ 12.75GHz -33dBm

100k ~ 880MHz 100k ~ 880MHz 880M ~ 915MHz 880M ~ 915MHz 915M ~ 1000Mz 915M ~ 1000MHz 1G ~ 1.71GHz 1G ~ 1.71GHz

1.71G ~ 1.785GHz 1.71G ~ 1.785GHz

1.785G ~ 12.75GHz 1.785G ~ 12.75GHz

30M ~ 1GHz -36dBm

1G ~ 4GHz -30dBm 30M ~ 880MHz 30M ~ 880MHz 880M ~ 915MHz

915M ~ 1000MHz 915M ~ 1000MHz 1G ~ 1.71GHz 1G ~ 1.71GHz

1.71G ~ 1.785GHz

1.785G~ 4GHz 1.785G~ 4GHz ??

0.1ppm

?5?

(RMS)

?20?

(PEAK)

GSM DCS

9k ~ 1GHz 1G ~ 1710MHz

1710M ~ 1785MHz 1785M ~ 12.75GHz

-60dBm -60dBm

-62dBm -62dBm

-60dBm -60dBm

-50dBm -50dBm

-56dBm -56dBm

-50dBm -50dBm 30M ~ 1GHz 1G ~ 1710MHz

1710M ~ 1785MHz 1785M ~ 4GHz

-57dBm

-59dBm

-57dBm

-47dBm

-53dBm

-47dBm

880M ~ 915MHz

1.71G ~ 1.785GHz

0.1ppm

?5?

(RMS)

?20?

(PEAK)

-39dBm

-33dBm

-30dBm

-36dBm

-30dBm

-57dBm

-59dBm

-57dBm

-47dBm

-53dBm

-47dBm

- 9 -

LGE Internal Use Only

2. PERFORMANCE

󳙂

󱭾

1) Frequency characteristic of transmission part -GSM Mode(continued)

7 Intermodulation attenuation

8 Trans mitter Output Powe r

Item

Frequency Error Under

Multipath and Interference

Condition

Due to

modulation

Output RF Spectrum

Due to

Switching

tran si ent

Burst tim ing Mas k IN

3dB below reference sensitivity 3dB below reference sensitivity

RA250: ±200Hz RA250: ±250Hz

HT100: ±100Hz HT100: ±250Hz

TU50: ±100Hz TU50: ±150Hz

TU3: ±150Hz TU1.5: ±200Hz

0 ~ 100kHz 0 ~ 100kHz

200kHz 200kHz

250kHz 250kHz

400kHz 400kHz

600 ~ 1800kHz 600 ~ 1800kHz

1800 ~ 3000kHz 1800 ~ 6000kHz

3000 ~ 6000kHz ³ 6000kHz

³ 6000kHz

400kHz 400kHz

600kHz 600kHz

1200kHz 1200kHz

1800kHz 1800kHz

Power control Power

Level (dBm) Level (dBm) (dB)

533 0 30 ±3

631 1 28 ±3

729 2 26 ±3

827 3 24 ±3

925 4 22 ±3

10 23 5 20 ±3

11 21 6 18 ±3

12 19 7 16 ±3

13 17 8 14 ±3

14 15 9 12 ±4

15 13 10 10 ±4

16 11 11 8 ±4

17 9 12 6 ±4

18 7 13 4 ±4

19 5 14 2 ±5

GSM DCS

Tolerance

+0.5dB +0.5dB

-30dB -30dB

-33dB -31dB

-60dB -33dB

-66dB -60dB

-69dB -60dB

-71dB -73dB

-77dB

-19dB -22dB

-21dB -24dB

-24dB -27dB

Frequency offset

Intermodulation product should be

Less than 55dB below the level of

Wanted signal Power control Power Tolerance

(dB)

±3

±5

15 0 ±5

Mask IN

800kHz

- 10 -

Only for training and service purposes

1) Frequency characteristic of transmission part -WCDMA Mode

35-15*(Δf-2.5) dBc @Δf= 2.5~3.5MHz

2. PERFORMANCE

1 Maximum Output Power

󶨔󴽐

Item

Standard

󴊃󴅐

Class3: +24 dBm (+1/-3dB) Class4: +21dBm(±2dB)

2 Frequency Error ± 0.1ppm

3 Open Loop Power control in uplink ± 9dB

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

4 Inner Loop Power control in uplink

group(10equal command group) +1 +8/+12 +16/+24

5 Minimum Output Power -50 dBm

Out-of-synchronization handling

of output power

Qin/Qout:DPCCH quality levels Toff@ DPCCH/Ior:-22->-28dB Ton@ DPCCH/ Ior:-24->-18dB

󵰛󶧿

under

@normal, ±12dB @extreme

󵰛󴕛

(3.84MHz)

Under (3.84MHz)

󵰛󶧿

7 Transmit OFF Power -56 dBm

8 Transmit ON/OFF Time Mask

±25us PRACH,CPCH, uplink c ompressed mode

±25us

9 Change of TFC

power varies according to the data rate DTX: DPCH off (minise interference between UE)

Power setting in uplink

10 ±3dB

compressed

󵰛󴕛

11 Occupied Bandwidth(OBW) 5 MHz

-35-1*(Δf-3.5) dBc @Δf=3.5~7.5MHz,1M

12 Spectrum emission Mask

-39 10*(Δf-7.5) dBc @Δf=7.5~8.5MHz,1M

-49 dBc @Δ f=8.5~12.5MHz,1M

Adjacent Channel Leakage Ratio

(ACLR)

33dB

43dB

(3.84M)

󵰛󶧿

Under (3.84M)

( after14slots transmission gap)

(99% )

Under (99%)

󵰛󶧿

@5MHz , ACP>-50dBm

󵰛󵕨

over

@10MHz , ACP>-50dBm

󵰛󵕨

over

- 11 -

LGE Internal Use Only

2. PERFORMANCE

1) Frequency characteristic of transmission part -WCDMA Mode(continued)

-36 dBm @f=9~150KHz, 1k BW

WCDMA

2100, 800

Spurious Emission

*:addition requirement

WCDMA

2100

WCDMA

800

15 Transmit Intermodulation

16 Error Vector Magnitude(EVM)

17 Peak code domain error

-36 dBm @f=150KHz~30MHz, 10k

-36 dBm @f=30~1000MHz, 100k

-30 dBm @f=1~12.75GHz, 1M

-41 dBm* @1893.5~1919.6MHz, 300k

-67 dBm* @925~935MHz, 100k

-79 dBm* @935~960MHz, 100k

-71 dBm* @1805~1880MHz, 100k

-60 dBm* @869~894MHz, 3.84M

-60 dBm* @1930~1990MHz, 3.84M

-60 dBm* @2110~2155MHz, 3.84M

-31 dBc @5MHz,Interferer -40dBc

-41 dBc @10MHz,Interferer -40dBc

under 17.5%

17.5 %

󵰛󶧿

( >-20dBm)

(@12.2k, 1DPDCH+1DPCCH)

-15 dB

under -15 dB

@SF=4, 768kbps , multi-co de

󵰛󶧿

transmission

- 12 -

Only for training and service purposes

2) Frequency characteristic of reception part - GSM Mode

󳙂

󱭾

2. PERFORMANCE

NO GSM DCS

Sensitivity (TCH/FS Class II)

Co-Channel Rejec tion

Adjacent

4 Intermodulation Rejec tion

Channel

Rejection

(TCH/FS Class II, RBER)

Item

(TCH/FS Class II,

RBE R, TUhigh/FH)

200kHz C/Ia1= -12dB C/Ia1= -12dB 400kHz C/Ia2= -44dB C/Ia2= -44dB

Blocking Response

-105dBm -105dBm

C/Ic= 7dB C/Ic= 7dB

Wanted S ignal: -98dB m Wanted S ignal: -96dB m

1’st interferer: -44dBm 1’st interferer: -44dBm

2’nd interferer: -45dBm 2’nd interferer: -44dBm

Wanted S ignal: -101dB m Wanted S ignal: -101dB m

Unwanted Signal: Depend on freq. Unwanted Signal: Depend on freq.

- 13 -

LGE Internal Use Only

2. PERFORMANCE

2) Frequency characteristic of reception part - WCDMA Mode

󶨔󴽐

Item

Standard

󴊃󴅐

18 Reference Sensivitivity Level -106.7dBm

-25 dBm

19 Maximum Input Level

over -25 dBm

-44dBm/3.84MHz(DPCH_Ec)

󵰛󵕨

UE@ +20dBm output power(class3)

20 Adjacent Channel Selectivity(ACS)

33 dB UE@ +20dBm output power(class3)

󵰛󵕨

over 33dB

-56 dBm/3.84MHz @10MHz UE@ +20dBm output power(class3)

In-band Blocking

-44 dBm/3.84MHz @15MHz UE@ +20dBm output power(class3)

-44 dBm/3.84MHz @f=2050~2095 & 2185~2230 MHz , band a) UE@ =20dBm output power(class3)

-30 dBm/3.84MHz @f=2025~2050 &

22 Out-band Blocking

2230~2255 MHz, band a) UE@ +20dBm output power(class3)

-15 dBm/3.84MHz @f=1~2025 & 2255~12500 MHz, band a) UE@ +20dBm output power(class3)

(3.84M)

under

󵰛󶧿

(3.84 MHz)

23 Spurious Response

UE@ +20dBm output power(class3)

-46 dBm CW@10MHz &

-44 dBm CW

24 Intermodulation Characteristic

-46dBm/3.84MHz @20MHz UE@ +20dBm output power(class3)

-57 dBm @f=9KHz~1GHz, 100k BW

WCDMA

2100, 800

-47 dBm @f=1~12.75GHz, 1M

-60 dBm @f=1920~1980MHz, 3.84MHz

Spurious Emission

WCDMA

2100

-60 dBm @f=2110~2170MHz, 3.84MHz

-60 dBm @f=824~849MHz, 3.84MHz

WCDMA

800

-60 dBm @f=869~894MHz, 3.84MHz

- 14 -

Only for training and service purposes

2. PERFORMANCE



2.4 Current consumption

Current consumption characteristic is demand of NTT docomo.(capacity of battery : 3.7V 900mAh)

(VT measurement, condition : Speaker off, LCD backlight On)

VTVoice CallStatic Stand-by

WCDMA

GSM

300 Hours (3mA) (DRX=2.56)

250 Hours (3.5mA) (Paging period = 5)

180 Min (260mA) (Tx=10dBm)

140 Min (330mA) (Tx=Max)

80 Min (550mA) (Tx=10dBm)

2.5 RSSI (Call (W2100 0dBm /EGSM Power level 19) : Cell Power)

GSMWCDMA

2 dBm-102.5 󰆚 2 dBmBAR 3 ->2

-95

-100

-105 2 dBm-107.5 󰆚 2 dBmBAR 1 ->0

Followed Network Notification< -113 󰆚 2dBmOut of area

2 dBm-105.5 󰆚 2 dBmBAR 2 ->1

- 15 -

LGE Internal Use Only

2. PERFORMANCE



2.6 Battery Bar

Indication

BAR 3 -> 2

(call maintenance over 40min)

BAR 2 -> 1

(call maintenance over 10min)

BAR 1 -> 0

(Icon Blinking)

Low battery message

Low battery pop-up

Power OFF during call

Power OFF at stand-by

3.72V  0.05V

3.62V  0.05V

3.30V  0.05V

BAR 2 -> 1, display one time

60s after Low battery message

Voltage

During Call stateDuring Idle state

3.62V  0.05V

3.52V  0.05V

3.30V  0.05V

BAR 1 -> 0

80s after Low battery message

- 16 -

Only for training and service purposes

2.7 Sound pressure Level

2. PERFORMANCE

examination itemNO

A C O U

S T

Sending Loudness Rating

(SLR)

Sending Frequency

Response (SFR)

Receiving Loudness Rating

(RLR)

Receiving Frequency

Response (RFR)

Side Tone Masking Rating

(STMR)

Echo Loss (EL)

Idle Noise-Sending (INS)

Idle Noise-Receiving (INR)

M/S

Examination standard

NOM

MAX

MASK INMAX

-43dBNOM

-153dBMAX

MASK INMAX

NOM

over 17dB

MAX

NOM

over 40dB

MAX

NOM

under -64dBm0p

MAX

under -54dBPA NOM

under -57dBPA MAX



3dB

C O U

Sending Loudness Rating

(SLR)

Receiving Loudness Rating

(RLR)

Side Tone Masking Rating

(STMR)

Echo Loss (EL)

Idle Noise-Sending (INS)

Idle Noise-Receiving (INR)

Head

set

NOM

83dB

MAX

-13dBNOM

-123dBMAX

NOM

over 25dB

MAX

NOM

over 40dB

MAX

NOM

under -55dBm0p

MAX

under -45dBPA NOM

under -40dBPA MAX

- 17 -

LGE Internal Use Only

2. PERFORMANCE

2.8 SAR characteristic

Conducted

Power [dBm]

GSM1900GSM1800GSM900WCDMA 800 WCDAM 2100Band

29.529.532.522.522.5

under 1.6 under 1.6under 1.6under 1.6under 1.6SAR(10g)[mW/g]

- 18 -

Only for training and service purposes

3. TECHNICAL BRIEF

L-06A



L-06A



3. TECHNICAL BRIEF

3.1 General Description

The L-06A supports UMTS-800, UMTS-2100, GSM-900, DCS-1800, and PCS-1900 based GSM/GPRS/UMTS. All

receivers and the UMTS transmitter use the radioOne

frequencies, directly converting signals between RF and baseband. The tri-band GSM transmitters use a

baseband-to-IF upconversion followed by an offset phase-locked loop that translates the GMSK-modulated or

8-PSK-modulated signal to RF.

Zero-IF architecture to eliminate intermediate

Fig 3.1-1 Block diagram of RF part

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

- 19 -

LGE Internal Use Only

3. TECHNICAL BRIEF

L-06A



A generic, high-level functional block diagram of L-06A is shown in Figure 3-1. One antenna collects base

station forward link signals and radiates handset reverse link signals. The antenna connects with receive and

transmit paths through a FEM(Front End Module) (plus two duplexers for UMTS high-band and low-band

operations).

The UMTS receive paths each include an LNA, an RF band-pass filter, and a downconverter that translate the

signal directly from RF-to-baseband using radioOne ZIF techniques.

The high-band UMTS receive path and low-band path are accommodated in the RTR6280 IC. 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 RTR6280 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 RTR6280 IC outputs

deliver fairly high-level RF signals that are first filtered by Tx SAWs and then amplified by their respective

UMTS PAs. The high- and low-band UMTS RF transmit signals emerge from the RTR6280 transceiver.

In the GSM receive path, the received RF signals are applied through their band-pass filters and

down-converted directly to baseband in the RTR6280 transceiver IC. These baseband outputs are shared with

the UMTS receiver and routed to the MSM IC for further signal processing. .

The GSM 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

- 20 -

Only for training and service purposes

3. TECHNICAL BRIEF

L-06A



L-06A 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.

- 21 -

LGE Internal Use Only

3. TECHNICAL BRIEF

L-06A



3.2 GSM Mode

3.2.1 GSM Receiver

The Dual-mode L-06A’s receiver functions are split between the three RFICs as follows:

■ UMTS-800, UMTS-2100, GSM-900, DCS-1800, and PCS-1900 modes use the RTR6280 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 SSBI-controlled parameters.

RF Front end consists of antenna, antenna switch module(LMSP43QL-771) which includes four RX

saw filters(GSM850, GSM900, DCS and PCS). The antenna switch module allows multiple

operating bands and modes to share the same antenna.

In L-06A, a common antenna connects to one of eight paths:

1) UMTS-800 Rx/Tx, 2) UMTS-1900 Rx/Tx, 3) GSM-900 Rx, 4) GSM-900 Tx,

5) DCS-1800 Rx, 6) PCS-1900 Rx, 7) DCS-1800 TX, 8) PCS-1900 TX.

UMTS operation requires simultaneous reception and transmission, so the UMTS

Rx/Tx connection is routed to a duplexer that separates receive and transmit signals.

GSM850/GSM900, DCS, and PCS operation is time division duplexed, so only the receiver

or transmitter is active at any time and a frequency duplexer is not required.

Table 3.2-1 Antenna Switch Module Control logic

- 22 -

Only for training and service purposes

3. TECHNICAL BRIEF

L-06A



The GSM900, DCS, and PCS receiver inputs of RTR6280 are connected directly to the transceiver front-end

circuits(filters and antenna switch module). GSM900, DCS, and PCS receiver inputs 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. The RTR6280 input stages include MSM-controlled gain adjustments that maximize

receiver dynamic range.

Since GSM900, 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 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.

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Fig 3.2-1 RTR6280 RX feature

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3.2.2 GSM Transmitter

The RTR6280 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 applictions and PCB characteristics based on pass-band symmetry about the

band center frequency, the suggested starting value is shown in Figure3.2.

Figure 3.2-2 GSM Transmitter matching

The RTR6280 IC is able to support GSM 850/1900 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. The low-band GSM. Tx sSAW can be eliminated because

ETSI spec requires mid channels to pass RX Band noise only.

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3.3 UMTS Mode

3.3.1 Receiver

The UMTS duplexer receiver outputs are routed to LNA circuits within the RTR6280 device.

The RTR6285/RTR6280 receive paths include four WCDMA Rx signal paths(two single-ended and two

differential) for one UMTS low-band and three UMTS high-bands.

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WCDMA_800_RX

WCDMA_2100_RX

Figure 3.3-1 RTR6280 IC functional block diagram

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The two RTR6285/RTR6280 UMTS single-ended inputs accept its UMTS 2100/1900/1800/1700 input signal

from the handset RF front-end filters. The UMTS Rx inputs are provided with onchip LNAs that amplify the

signal before second-stage filters that provide differential signal to a shared downconverter. This second-

stage input is configured differentially to optimize secondorder inter-modulation 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 with the MSM IC.

The RTR6285/RTR6280 UMTS differential input paths stay on-chip; off-chip inter-stage filtering is not required.

Other than this, the architecture is similar to the single-ended inputs. The UMTS duplexer receiver output is

routed to LNA circuits within the RTR6280 device. UMTS LNA circuits(one for low-band UMTS and one for

high-band UMTS path) separated from all other receive functions contained within the RTR6280 IC to improve

mixer LO to RF isolation- a critical parameter in the ZIF architecture. Isolation is further improved using high-

reverse isolation circuits in the LNA designs

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3.3.2 Transmitter

The RTR6285/RTR6280 transmit includes four transmit signal paths with five outputs (three high bands and

two low bands) supporting multi-band and multi-mode GSM/GPRS/EDGE polar transmit and WCDMA/HSDPA

transmit architectures. The transmit path begins with differential baseband signals (I and Q) from the MSM

device.

These analog input signals are buffered, filtered by low-pass filters, amplified, and then applied to the

quadrature upconverter mixers. The upconverter outputs are amplified by multiple variable gain stages that

provide transmit AGC control. SSBI control from the MSM IC is used to generate the gain range control signal.

The AGC outputs are then applied to the high-band and low-output driver amplifiers; the specified driver

amplifier output level is achieved while supporting the GSM/EDGE and UMTS transmit standard’s

requirements for GSM ORFS, carrier and image suppression, WCDMA ACLR, spurious emissions, Rx-band noise,

and so forth. Again, the upconverter LO signals are generated by circuits described in Section 1.2.3. These

upconverters translate the polar GMSK-modulated or 8-PSK modulated baseband PM signals and/or WCDMA

baseband signals directly to the RF signals, which are filtered and fed into the GSM/EDGE polar PA and/or

WCDMA PA. The WCDMA TX power is coupled back to the RTR6285/RTR6280 internal power detector input

pin, PWD_DET_IN, using a coupler for power measurement.

The low-band drive amplifiers are used to transmit the polar phase modulated (PM) signal for GSM/EDGE

850/900 while the high-band driver amplifiers are for the GSM/EDGE 1800/1900.

By using the radioOne architecture, the same high-band transmit path can be used to transmit the UMTS

2100/1900/1800/1700 signal, and the low-band transmit path can be used to transmit the UMTS 800/850/900

signal, depending on the application. The envelope path is used in polar mode of operation for GSM and

EDGE. Input from the MSM IC, the baseband envelope (AM) signal, is applied directly to the ramp control pin

of the GSM/EDGE polar PA to modulate the power supply of the PA so that the polar modulated GSM/EDGE

signal in the MSM can be recovered and transmitted.

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WCDMA_2100_TX

WCDMA_800_TX

Fig.3.3-2 RTR6280 IC functional block diagram

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3.4 LO Phase-locked Loop

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-to-

baseband and from baseband-to-RF.

Two fully functional fractional-N synthesizers, including VCOs and loop filters, are integrated within the

RTR6285/RTR6280 IC. In addition, the RTR6285 has a third synthesizer used for GPS operation. The first

synthesizer (PLL1) in the RTR6285/6280 creates the transceiver LOs that support the UMTS transmitter, and all

four GSM band receivers and transmitters including: GSM 850, GSM 900, GSM 1800, and GSM 1900. The

second synthesizer (PLL2) in the RTR6285/RTR6280 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/RTR6280 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/RTR6280 ICs have the advantage of more flexible loop bandwidth

control, fast lock time, and low-integrated phase error.

Fig.3.4-1. RTR6280 PLL’s functional block diagram

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LG L-06A Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual