LG KU380 Service Manual

Date: December, 2007 / Issue 1.0

Service Manual

KU380

Service Manual

Model : KU380

Internal Use Only

- 3 -

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 generation and distribution circuits ......25

3.5 Off-chip RF Components ...........................25

3.6 Digital Baseband(DBB/MSM6245) ............34

3.7 Subsystem(MSM6245) ..............................37

3.8 Power Block...............................................45

3.9 External memory interface.........................50

3.10 H/W Sub System .....................................52

3.11 Main Features..........................................68

4. TROUBLE SHOOTING.......................73

4.1 RF Component ..........................................73

4.2 SIGNAL PATH_UMTS RF .........................75

4.3 SIGNAL PATH_GSM RF ...........................76

4.4 Checking VC-TCXO Block.........................77

4.5 Checking Front-End Module Block ............79

4.6 Checking UMTS Block...............................81

4.7 Checking GSM Block.................................86

4.8 Checking Bluetooth Block..........................92

4.9 Power ON Troubleshooting .......................94

4.10 Charger Troubleshooting .........................96

4.11 USB Troubleshooting...............................99

4.12 SIM Detect Troubleshooting ..................100

4.13 Camera Troubleshooting .......................102

4.14 Keypad Backlight Troubleshooting ........105

4.15 Main LCD Troubleshooting ....................106

4.16 Receiver Path ........................................107

4.17 Headset path .........................................109

4.18 Speaker phone path ..............................111

4.19 Main microphone ...................................113

4.20 Headset microphone..............................115

4.21 Vibrator ..................................................117

5. DOWNLOAD .....................................118

5.1 Introduction ..............................................118

5.2 Downloading Procedure ..........................118

5.3 Troubleshooting Download Errors ..........131

5.4 Caution ....................................................136

6. BLOCK DIAGRAM ...........................137

6.1 GSM & UMTS RF Block ..........................137

6.2 Interface Diagram ....................................139

7. CIRCUIT DIAGRAM..........................143

8. BGA IC PIN MAP..............................149

9. PCB LAYOUT ...................................153

10. Calibration & RF Auto Test

Program (Hot Kimchi) ...................159

10.1 Configuration of HOT KIMCHI ...............159

10.2 How to use HOT KIMCHI.......................162

11. Factory Test Mode .........................164

11.1 Factory Test Mode.................................164

11.2 WCDMA Test Mode...............................164

11.3 GSM Test Mode.....................................165

12. EXPLODED VIEW & REPLACEMENT

PART LIST ..................................... 167

12.1 EXPLODED VIEW ................................ 167

12.2 Replacement Parts

<Mechanic component> ....................... 169

<Main component> ............................... 172

12.3 Accessory ............................................. 188

Table Of Contents

LGE Internal Use Only

- 4 -

LGE Internal Use Only

Only for training and service purposes

LGE Internal Use Only

- 5 -

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

LGE Internal Use Only

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

- 6 -

LGE Internal Use Only

2. PERFORMANCE

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2.1 System Overview

2. PERFORMANCE

Item Specification

Shape GSM900/1800/1900/EDGE and WCDMA2100 - Slide type Handset

Size 96 X 45 X 17.9 mm

Weight Under 97 g (with 900mAh Battery)

Power 3.7 V normal, 900 mAh Li-Ion

Talk Time Over 160 min (WCDMA, Tx=12 dBm, Voice)

with 1000mAh) Over 160 min (GSM, Max Tx Power, Voice)

Standby Time Over 200 Hrs (WCDMA, DRX=1.28)

(with 1000mAh) Over 270 Hrs (GSM, Paging period=9)

Antenna Internal type

LCD Main 1.76” TFT, QCIF, 262K

LCD Backlight White LED Back Light

Camera 1.3 Mega pixel + VGA Video Call Camera

Vibrator Yes ( Coin Type)

LED Indicator No

MIC Yes

Receiver Yes

Earphone Jack Yes (18 pin)

Connectivity Bluetooth, USB

External Memory Yes(Micro SD)

I/O Connect 18 Pin

LGE Internal Use Only

Only for training and service purposes

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

- 8 -

Item Specification

Voltage 3.7 V(Typ), 3.2 V(Min), [Shut Down : 3.2 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

1 Spurious 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

LGE Internal Use Only

2. PERFORMANCE

- 9 -

** 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

3 Frequency Error ±0.1ppm ±0.1ppm

4 Phase Error

±5(RMS) ±5(RMS)

±20(PEAK) ±20(PEAK)

3dB below reference sensitivity 3dB below reference sensitivity

Frequency Error RA250 : ±200Hz RA250: ±250Hz

5 Under 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 -66dB 600 ~ 1800kHz -60dB

6 1800 ~ 3000kHz -69dB 1800 ~ 6000kHz -65dB

Spectrum

3000 ~ 6000kHz -71dB ≥6000kHz -73dB

≥6000kHz -77dB

Due to

400kHz -19dB 400kHz -22dB

Switching

600kHz -21dB 600kHz -24dB

transient

1200kHz -21dB 1200kHz -24dB

1800kHz -24dB 1800kHz -27dB

LGE Internal Use Only

Only for training and service purposes

2. PERFORMANCE

- 10 -

No Item GSM DCS & PCS

Frequency offset 800kHz

7 Intermodulation 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

8 Transmitter 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

9 Burst timing Mask IN Mask IN

LGE Internal Use Only

2. PERFORMANCE

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2) Transmitter - WCDMA Mode

No Item Specification

1 Maximum Output Power Class 3 : +24dBm(+1/-3dB)

2 Frequency Error ±0.1ppm

3 Open 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

4 Inner 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

5 Minimum Output Power -50dBm(3.84MHz)

Qin/Qout : PCCH quality levels

6 Out-of-synchronization handling of output power Toff@DPCCH/Ior : -22 -> -28dB

Ton@DPCCH/Ior : -24 -> -18dB

7 Transmit OFF Power -56dBm(3.84MHz)

8 Transmit ON/OFF Time Mask

±25us

PRACH,CPCH,uplinlk compressed mode

±25us

9 Change 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

LGE Internal Use Only

Only for training and service purposes

3)Receiver - GSM Mode

2. PERFORMANCE

- 12 -

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

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

Sensitivity (TCH/FS Class II) -105dBm -105dBm

Co-Channel Rejection

C/Ic=7dB Storage -30 ~ +85

(TCH/FS Class II, RBER, TU high/FH)

3 Adjacent Channel 200kHz C/Ia1=-12dB C/Ia1=-12dB

Rejection 400kHz C/Ia2=-44dB C/Ia2=-44dB

Wanted Signal :-98dBm 1st Wanted Signal :-96dBm 1st

Intermodulation Rejection interferer:-44dBm 2nd interferer:-44dBm 2nd

interferer:-45dBm interferer:-44dBm

Blocking Response Wanted Signal :-101dBm Wanted Signal :-101dBm

(TCH/FS Class II, RBER)

Unwanted : Depend on Frequency Unwanted : Depend on Frequency

LGE Internal Use Only

2. PERFORMANCE

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5) Receiver - WCDMA Mode

No Item Specification

1 Reference Sensitivity Level -106.7 dBm(3.84 MHz)

-25dBm(3.84MHz)

2 Maximum Input Level -44dBm/3.84MHz(DPCH_Ec)

UE@+20dBm output power(Class3)

3 Adjacent 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

5 Out-band Blocking 2230~2255MHz

UE@+20dBm output power(Class3)

-15dBm/3.84MHz@f=1~2025 and

2255~12500MHz

UE@+20dBm output power(Class3)

6 Spurious Response

-44dBm CW

UE@+20dBm output power(Class3)

-46dBm CW@10MHz

7 Intermodulation Characteristic -46dBm/3.84MHz@20MHz

UE@+20dBm output power(Class3)

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

8 Spurious Emissions -47dBm@f=1~12.5GHz, 1M BW

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

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

LGE Internal Use Only

Only for training and service purposes

2. PERFORMANCE

- 14 -

2.4 Current Consumption

1) KU380 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)

2.5 RSSI BAR

Stand by Voice Call VT

WCDMA

Under 4.5 mA Under 350 mA Under 410mA

(DRX=1.28) (Tx=12dBm) (Tx=12dBm)

Under 3.3 mA Under 350 mA

GSM Paging=9 period (Max Tx Power)

Level Change WCDMA GSM

BAR 4 → 3 -85 ± 2 dBm -91 ± 2 dBm

BAR 3 → 2 -95 ± 2 dBm -96 ± 2 dBm

BAR 2 → 1 -106 ± 2 dBm -101 ± 2 dBm

BAR 1 → 0 -111 ± 2 dBm -106 ± 2 dBm

LGE Internal Use Only

2.6 Battery BAR

2. PERFORMANCE

- 15 -

Indication Standby

Bar 4 Over 3.83 ± 0.05V

Bar 4 → 3 3.82 ± 0.05V

Bar 3 → 2 3.73 ± 0.05V

Bar 2 → 1 3.68 ± 0.05V

Bar 1 → Empty 3.58 ± 0.05V

Low Voltage, 3.58 ± 0.05V (Stand-by) / 3.58 ± 0.05V (Talk)

Warning message+ Blinking [Interval : 3min(Stand-by) / 1min(Talk)]

Power Off 3.20 ± 0.05V

LGE Internal Use Only

Only for training and service purposes

2. PERFORMANCE

- 16 -

2.7 Sound Pressure Level

2.8 Charging

• Charging Method : CC & CV (Constant Current and Constant Voltage)

• Maximum Charging Voltage : 4.2 V

• Maximum Charging Current : 600 mA

• Normal Battery Capacity : 900 mAh

• Charging Time : Max 3.5 hours (except for trickle charging time)

• Full charging indication current (charging icon stop current) : 100 mA

• Cut-off voltage : 3.20 V

No Test Item Specification

1 Sending Loudness Rating (SLR) 8 ±3 dB

2 Receiving Loudness Rating (RLR)

Nor -4 ± 3 dB

Max -15 ± 3 dB

3 Side Tone Masking Rating (STMR) Min 17 dB

4 Echo Loss (EL) Min 40 dB

5 Idle Noise-Sending (INS) Max -64 dBm0p

6 Idle Noise-Receiving (INR)

Nor Under -47 dBPA

Max Under -36 dBPA

7 Sending Loudness Rating (SLR) 8±3dB

8 Receiving Loudness Rating (RLR)

Nor -1 ±3 dB

Max -12 ±3 dB

9 Side Tone Masking Rating (STMR) Min 25 dB

10 Echo Loss (EL) Min 40 dB

11 Idle Noise-Sending (INS) Max -55 dBm0p

12 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)

-. Acoustic (Max Vol.)

MS/Headset SLR : 8 ±3dB

MS/Headset RLR : -15 ± 3dB/-12

(SLR/RLR : Mid-value setting)

Headset

MS and

Headset

Max

Under -62 dBm

LGE Internal Use Only

3. TECHNICAL BRIEF

- 17 -

3.1 General Description

The KU380 supports UMTS-2100, GSM-900, DCS-1800, and PCS-1900 based GSM/GPRS/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 upconversion followed by an offset phase-locked loop that translates the GMSKmodulated signal to RF.

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

3. TECHNICAL BRIEF

Front

End

Module

Duplexer

RTR6275

WCDMA

PAM

MSM6245

WCDMA

TX SAW

WCDMA

RX SAW

PM6650

-2M

GSM PAM

GSM

TX SAW

COUPLER

VCTCXO

Bluetooth

RF Module

U-SIM

1.3M CAM

USB

MIC

SPK/RCV

KEYPAD

NAND, SDRAM

FLASH

MAIN LCD

VGA CAM

GSM900 Rx

GSM1800 Rx

GSM1900 Rx

GSM900 Tx

GSM1800/1900 Tx

AntSW Logi c

WCDMA2100 Tx

WCDMA2100 Rx

GSM

VCO

WCDMA

VCO

HDET

GSM Block

WCDMA Block

[Fig 1.1] Block diagram of RF part

LGE Internal Use Only

Only for training and service purposes

A generic, high-level functional block diagram of KU380 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 FEM(Front End Module).

The UMTS receive path each include a LNA, a RF band-pass filter, and a downconverter that translate the signal directly from RF-to-baseband using radioOne ZIF technique. The RFIC 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 RTR6275 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 RTR6275 IC outputs deliver fairly high-level RF signals that are first filtered by Tx SAWs and then amplified by their respective UMTS PA. The high- and low-band UMTS RF transmit signals emerge from the RTR6275 transceiver.

In the GSM receive paths, the received RF signals are applied through their band-pass filters and down-converted directly to baseband in the RTR6275 transceiver IC. These baseband outputs are shared with the UMTS receiver and routed to the MSM IC for further signal processing.

The GSM transmit paths employ one stage of up-conversion and, in order to improve efficiency.

1. The on-chip quadrature up-converter translates the GMSK-modulated signal to a constant envelope

phase signal at RF;

2. The amplitude-modulated (AM) component is applied to the ramping control pin of power amplifier

from a DAC within the MSM

KU380 power supply voltages are managed and regulated by the PM6650 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

- 18 -

LGE Internal Use Only

3. TECHNICAL BRIEF

- 19 -

3.2 GSM Mode

3.2.1 GSM Receiver

The Dual-mode KU380’s receiver functions are split among the three RFIC’s as follows:

• GSM-900, DCS-1800, and PCS-1900 UMTS-2100 modes use the RTR6275 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.

RF Front end consists of antenna, antenna switch module(D5011) which includes three RX saw filters(GSM900, DCS and PCS). The antenna switch module allows multiple operating bands and modes to share the same antenna. In KU380, a common antenna connects to one of six paths: 1) UMTS-2100 Rx/Tx, 2) GSM-900 Rx, 3) GSM-900 Tx, 4) DCS-1800 Rx, and 5) DCS-1800 Tx, PCS1900 Tx(High Band Tx’s share the same path), 6) PCS-1900 Rx. UMTS operation requires simultaneous reception and transmission, so the UMTS Rx/Tx connection is routed to a duplexer that separates receive and transmit signals. The 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.

The 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.

[Table 1.1] Antenna Switch Module Control logic

LGE Internal Use Only

Only for training and service purposes

The GSM900, DCS, and PCS receiver inputs of RTR6275 are connected directly to the transceiver front-end circuits(filters and antenna switch module). The 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

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 GSM900, DCS, and PCS receive signals are routed to the RTR6275 through band selection filters and matching networks that transform single-ended 50-Ω. sources to differential impedances optimized for gain and noise figure. The RTR input uses a differential configuration to improve second-order intermodulation and common mode rejection performance. The RTR6275 input stages include MSMcontrolled 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 MSM6245 IC for further processing (an interface shared with the RFR6275 UMTS receiver outputs).

3. TECHNICAL BRIEF

- 20 -

LGE Internal Use Only

3. TECHNICAL BRIEF

- 21 -

[Fig 1.2] RTR6275 RX feature

LGE Internal Use Only

Only for training and service purposes

3.2.2 GSM Transmitter

The RTR6275 transmitter outputs(DA_HB2_OUT and DA_LB1_OUT)include on-chip output matching inductors. The 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 passband symmetry about the band center frequency, the suggested starting value is shown in Figure1.2.

The RTR6275 IC is able to support GSM 900 and GSM 1800/1900 mode transmitting. This design guideline shows a tri-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 path also includes a Tx-band SAW filter to remove noise-spurious components and noise that would be amplified by the PA and appear in the GSM Rx band

3. TECHNICAL BRIEF

- 22 -

[Fig 1.3] GSM Transmitter matching

6pF

12p

51Ω

91Ω91Ω

39Ω

100Ω100Ω

LGE Internal Use Only

3. TECHNICAL BRIEF

- 23 -

3.3 UMTS Mode

3.3.1 Receiver

The UMTS duplexer receiver output is routed to LNA circuits within the RTR6275 device. The UMTS Rx input is provided with an on-chip LNA that amplifies the signal before a second stage filter that provides differential downconverter. This second stage input is configured differentially to optimize second-order intermodulation and common mode rejection performance. The gain of the UMTS frontend 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 RFtobaseband 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 RTR6275 is downconverting GSM signals and on when the UMTS is operating.

3.3.2 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 up-converter 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 50-Ω interface.

The RTR6275 UMTS output is routed to its power amplifier through a bandpass filter, and delivers fairly high-level 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 RTR6275 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 PLL1, the LO generation and distribution circuits create the necessary LO signals for different frequency converters. The UMTS transmitter also employs the ZIF architecture to translate the signal directly from baseband to RF. This requires FLOto equal FRF, and the RTR6275 IC design achieves this without allowing F

VCO

to equal FRF. The RTR6275 IC is able to support UMTS 2100/1900 and UMTS 850 mode transmitting. This design guideline shows only UMTS 2100 applications.

LGE Internal Use Only

Only for training and service purposes

3. TECHNICAL BRIEF

- 24 -

[Figure 1.4] RTR6275 IC functional block diagram

WCDMA_2100_TX

WCDMA_2100_RX

LGE Internal Use Only

3.4 LO generation and distribution circuits

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 and UMTS band upconverters and downconverters; with the help of these LO generation and distribution circuits, 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 RTR6275 IC. The first synthesizer (PLL1) creates the transceiver LOs that support the UMTS 2100/1900/1800 transmitter, and all four GSM band receivers and transmitters including: GSM 850, GSM 900, GSM 1800, and GSM 1900. The second synthesizer (PLL2) provides the LO for the UMTS 2100/1900/1800 receiver. An external TCXO input signal is required to provide the synthesizer frequency reference to which the PLL is phase and frequency locked. The RTR6275 IC integrates most of PLL loop filter components on-chip except two off-chip loop filter series capacitors, and significantly reduces off-chip component requirement. With the integrated fractional-N PLL synthesizers, the RTR6275 has the advantages of more flexible loop bandwidth control, fast lock time, and low-integrated phase error

3.5 Off-chip RF Components

3.5.1 WCDMA PAM (U104: AWT6277R)

The UMTS PA output power is monitored by l power detector circuits(U101 : RTR6275) . This detector voltage can be used for transmitter calibration and monitor to meet RF system

3. TECHNICAL BRIEF

- 25 -

[Figure 1.5] WCDMA PAM, Duplexer, Coupler

WCDMA

7dB

NEAR TO PAM

20dB

NEAR TO PAM

C154

3.9p

R122

C155

10p

TR100

KRX102U

100p

C158

GND1

GND2

GND3

GND4

GND5

RFIN

RFOUT

VCC1VCC2

VMODE

4 5

VREF

U104AWT6277R

FL101

G12G2

50OHM

COUP

OUT

EFCH1950TDF1

CP0402A1950DNTR

U103

C151

L123

1.8nH

L126 12nH

L121

5.6nH

ANT

PGND RX

1 2

ACMD-7602

FL102

R123

130

C157 NA

L122 NA

4.7u

C149

C148

8.2p

C162 100p

130

R124

L131

L127

R121

15nH

C152

+VPWR

PA_R0

+VPWR

PA_ON

VREG_TCXO_2.85V

PWR_DET

LGE Internal Use Only

Only for training and service purposes

3.5.2 VCTCXO (X100 : DSA321SCE-19.2M)

The Voltage Controlled Temperature Compensated Crystal Oscillator (VCTCXO) provides the reference frequency for all RFIC synthesizers as well as clock generation functions within the MSM6245 IC. The oscillator frequency is controlled by the MSM6245 IC. TRK_LO_ADJ pulse density modulated signal in the same manner as the transmit gain control TX_AGC_ADJ. A two-pole RC lowpass filter is recommended on this control line.

The PM6650 IC controls the handset power-up sequence, including a special VCTCXO warm-up interval before other circuits are turned on. This warm-up interval (as well as other TCXO controller functions) is enabled by the MSM TCXO_EN line . The PM6650 IC VREG_TCXO regulated output voltage is used to power the VCTCXO and is enabled before most other regulated outputs. Any GSM mode power control circuits within the MSM6245 IC require a reference voltage for proper operation and sufficient accuracy. Connecting the PM6650 IC REF_OUT directly to the MSM6245 IC GSM_PA_PWR_CTL_REF provides this reference. This sensitive analog signal needs a 0.1 µF low frequency filter near to MSM side, and isolate from digital logic and clock traces with ground on both sides, plus ground above and below if routed on internal layers.

3.5.3 Front-End Module (U100 : D5011)

This equipment uses a single antenna to support all handset operating modes, with an antenna switch module select the operating frequency and band. UMTS operation requires simultaneous reception and transmission, so the UMTS Rx/Tx connection is routed to a duplexer that separates receive and transmit signals. The active connection is MSM-selected by three control lines (GPIO[9], GPIO[10]). Two GPIO are programmed to be ANT_SEL0_N, ANT_SEL1_N) respectively.

3. TECHNICAL BRIEF

- 26 -

[Table 1.2] Front End Module control logic

LGE Internal Use Only

3. TECHNICAL BRIEF

- 27 -

3.5.4 PMIC Functional Block Diagram (U300 : PM6650-2M)

• Input power management

- Valid external supply attachment and removal detection

- Supports unregulated (closed-loop) external charger supplies and USB supplies as input power sources

- Supports lithium-ion main batteries

- Trickle, constant current, constant voltage, and pulsed charging of the main battery

- Supports coin cell backup battery (including charging)

- Battery voltage detectors with programmable thresholds

- VDD collapse protection

- Charger current regulation and real-time monitoring for over-current protection

- Charger transistor protection by power limit control

- Control drivers for two external pass transistors and one external battery MOSFET MOSFET is optional

- Voltage, current, and power control loops

- Automated recovery from sudden momentary power loss

• Output voltage regulation

- One boost (step-up) switched-mode power supply (SMPS) for driving white LEDs and hosting USBOTG

- Three buck (step-down) switched-mode power supplies that efficiently generate MSMC, MSME, and PA (or second MSMC) supply voltages

- Supports dynamic voltage scaling (DVS) for MSMC and PA

- Eleven low dropout regulator circuits with programmable output voltages, implemented using three different current ratings: 300 mA (two), 150 mA (six), and 50 mA (three). These can be used to power MSMA, MSMP, RFRX1, RFRX2, RFTX, SYNT, TCXO, WLAN, MMC, USB, and RUIM circuits.

- All regulators can be individually enabled/disabled for power savings

- Low power mode available on MSMA and MSMP regulators

- All regulated outputs are derived from a common bandgap reference - close tracking

• Integrated handset-level housekeeping functions reduces external parts count, size, cost

- Analog multiplexer selects from 8 internal and up to 18 external inputs

- Multiplexer output’s offset and gain are adjusted, increasing the effective ADC resolution

- Adjusted multiplexer output is buffered and routed to an MSM device ADC

- Dual oscillators - 32.768 kHz off-chip crystal and on-chip RC assures MSM device sleep clock

- Crystal oscillator detector and automated switch-over upon lost oscillation

- Real time clock for tracking time and generating associated alarms

- On-chip adjustments minimize crystal oscillator frequency errors

- Circuits control TCXO warm-up and synchronize, deglitch, and buffer the TCXO signal

- TCXO buffer control for optimal QPH/catnap timing

- Three-stage over-temperature protection (smart thermal control)

• Integrated handset-level user interfaces

- Four programmable current sinks recommended as keypad backlight, LCD backlight, camera flash, and general-purpose drivers

- Vibration motor driver programmable from 1.2 to 3.1V in 100 mV increments

- Speaker driver with programmable gain, turn-on time, and muting; differential operation (drives external |8 Ω speakers with volume controlled 500 mW)

LGE Internal Use Only

Only for training and service purposes

• IC-level interfaces

- MSM device-compatible 3-line SBI for efficient initialization, status, and control

- Supports the MSM device’s interrupt processing with an internal interrupt manager

- Many functions monitored and reported through real-time and interrupt status signals

- Dedicated circuits for controlled power-on sequencing, including the MSM device’s reset signal

- Several events continuously monitored for triggering power-on/power-off sequences

- Supports and orchestrates soft resets

- USB-OTG transceiver for full-speed (12 Mb/s) and low speed (1.5 Mb/s) interfacing of the MSM device to computers as a USB peripheral, or connecting the MSM device to other peripherals

- RUIM level translators enable MSM device interfacing with external modules

• Twelve multi-purpose pins that can be configured as digital or analog I/Os, bi-directional I/Os, or current sinks. Default functions support the RUIM level translators, power-on circuits, analog multiplexer inputs, an LED driver, and a reference voltage buffer.

• Highly integrated functionality in a small package - 84-pin BCCS with a large center slug for electrical ground, mechanical stability, and thermal relief.

3. TECHNICAL BRIEF

- 28 -

[Figure 1.6] MSM6245 Interface

LGE Internal Use Only

3. TECHNICAL BRIEF

- 29 -

[Figure1.7] PM6650 Block Diagram

LGE Internal Use Only

Only for training and service purposes

3.5.5 GSM PAM (U102 : SKY77329)

The SKY77329 Power Amplifier Module (PAM) is designed in a compact form factor for quad-band cellular handsets comprising GSM850/900, DCS1800, PCS1900, and supports Class 12 General Packet Radio Service (GPRS) multi-slot operation. The module consists of a GSM850/900 PA block and a DCS1800/PCS1900 PA block, impedance matching circuitry for 50 Ω input and output impedances, and a Power Amplifier Control (PAC) block. A custom CMOS integrated circuit provides the internal PAC function and interface circuitry. Two separate Heterojunction Bipolar Transistor (HBT) PA blocks are fabricated onto InGaP/GaAs die; one supports the GSM850/900 bands, the other supports the DCS1800 and PCS1900 bands. Both PA blocks share common power supply pins to distribute current. The GaAs die, the silicon die, and the passive components are mounted on a multi-layer laminate substrate and the entire assembly is encapsulated with plastic overmold.

3. TECHNICAL BRIEF

- 30 -

[Figure 1. 8] GSM PAM Schematic

GSM_PA_BAND

NEAR TO PAM

HIGH

10dB

DCS/PCS

MODE

6dB

LOW GSM

C122

8.2p

C131 68p

R111

C136 33p

91 R112

C133 NA

L117

1.5nH

18nH

L115

2.2K

R110

8.2nH

L116

15p

C144

R118 100ohm

C134

15p

C143

R115

C132 33u

PGND7

PGND825PGND9

RSVD18RSVD212RSVD3

TX_EN

VAPC

VBATT

PGND1

PGND10

PGND1127PGND12

PGND13

PGND14

PGND15

PGND16

PGND17

PGND18

PGND19

PGND2

PGND20

PGND319PGND4

PGND5

PGND6

SKY77329

U102

DCS_PCS_IN

DCS_PCS_OUT

GND110GND2

GND3

GND4

GND5

GSM_IN

GSM_OUT

R11391

100ohm

R117

FL100

EFCH897MTDB1

G12G2

100ohmR119

R116

100ohm

DCS_PCS_TX

+VPWR

GSM_PA_RAMP

GSM_PA_BAND

GSM_PA_EN

GSM_TX

LGE Internal Use Only

3. TECHNICAL BRIEF

- 31 -

3.5.6 UMTS Duplexer(FL102:ACMD-7602)

A UMTS duplexer splits a single operating band into receive and transmit paths. Important performance requirements include;

• Insertion loss . this component is also in the receive and transmit paths ; In the KU380 typical losses : UMTS2100_ Tx = 1.2 dB, UMTS2100_ Rx = 1.4 dB

• Out-of-band rejection or attenuation. the duplexer provides input selectivity for the receiver, output filtering for the transmitter, and isolation between the two. Rejection levels for both paths are specified over a number of frequency ranges. Two Tx-to-Rx isolation levels are critical to receiver performance:

• Rx-band isolation. the transmitter is specified for out-of-band noise falling into the Rx band. This noise leaks from the transmit path into the receive path, and must be limited to avoid degrading receiver sensitivity. The required Rx-band isolation depends on the PA out of-band noise levels and Rx-band losses between the PA and LNA. Minimum duplexer Rx band isolation value is about 51 dB.

• Tx-band isolation the transmit channel power also leaks into the receiver. In this case, the leakage is outside the receiver passband but at a relatively high level. It combines with Rx band jammers to create cross-modulation products that fall in-band to desensitize the receiver. The required Tx-band isolation depends on the PA channel power and Tx-band losses between the PA and LNA. Minimum duplexer Tx-band isolation value is about 58dB.

• Passband ripple the loss of this fairly narrowband device is not flat across its passband. Passband ripple increases the receive or transmit insertion loss at specific frequencies, creating performance variations across the band.s channels, and should be controlled.

• Return loss . minimize mismatch losses with typical return losses of 10 dB or more (VSWR <2:1).

• Power handling high power levels in the transmit path must be accommodated without degraded performance. The specified level depends on the operating band class and mobile station class (per the applicable standard), as well as circuit losses and antenna EIRP. Several duplexer characteristics depend upon its source and load impedances. QUALCOMM strongly recommends an isolator be used between the UMTS PA and duplexer to assure proper performance.

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LG KU380 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual