LG KS20 Service Manual

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......................................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/MSM7200) ............35

3.7 Hardware Architecture ...............................37

3.8. Subsystem(MSM7200) .............................39

3.9. Power Block..............................................42

3.10. External memory interface......................47

3.11. H/W Sub System ....................................49

3.12. Main Features.........................................76

4. TROUBLE SHOOTING.......................82

4.1 RF Component ..........................................82

4.2 SIGNAL PATH_UMTS RF .........................85

4.3 SIGNAL PATH_GSM RF ...........................86

4.4 Checking VCTCXO Block ..........................87

4.5 Checking Front-End Module Block ............89

4.6 Checking UMTS Block...............................91

4.7 Checking GSM Block.................................96

4.8 Checking Bluetooth Block........................102

4.9 Checking WLAN Block.............................104

4.10 Power ON Troubleshooting ...................108

4.11 Charger Troubleshooting .......................110

4.12 USB Troubleshooting.............................113

4.13 SIM Detect Troubleshooting ..................115

4.14 Camera Troubleshooting .......................117

4.15 Keypad Backlight Troubleshooting ........120

4.16 Main LCD Troubleshooting ....................121

4.17 Receiver Path ........................................122

4.18 Headset path .........................................124

4.19 Speaker phone path ..............................126

4.20 Main microphone ...................................128

4.21 Headset microphone..............................130

4.22 Vibrator ..................................................132

5. DOWNLOAD.....................................133

5.1 KS20 DOWNLOAD..................................133

6. BLOCK DIAGRAM ...........................146

6.1 GSM & UMTS RF Block ..........................146

6.2 Interface Diagram ....................................148

7. Circuit Diagram................................153

8. BGA IC PIN MAP..............................163

8. PCB LAYOUT ...................................169

9. Calibration & RF Auto Test

Program (Hot Kimchi) .....................177

9.1 Configuration of HOT KIMCHI .................177

9.2 How to use HOT KIMCHI.........................180

10. Phone Test Mode _ 3G smart

Phone KS20 ...................................182

11. EXPLODED VIEW & REPLACEMENT

PART LIST ..................................... 189

11.1 EXPLODED VIEW ................................ 189

11.2 Replacement Parts

<Mechanic component> ....................... 191

<Main component> ............................... 193

11.3 Accessory ............................................. 209

- 3 -

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 commoncarrier telecommunication service of facilities accessed through or connected to it. The manufacturer will not be responsible for any charges that result from such unauthorized use.

B. Incidence of Harm

If a telephone company determines that the equipment provided to customer is faulty and possibly causing harm or interruption in service to the telephone network, it should disconnect telephone service until repair can be done. A telephone company may temporarily disconnect service as long as repair is not done.

C. Changes in Service

A local telephone company may make changes in its communications facilities or procedure. If these changes could reasonably be expected to affect the use of the phones or compatibility with the net work, the telephone company is required to give advanced written notice to the user, allowing the user to take appropriate steps to maintain telephone service.

D. Maintenance Limitations

Maintenance limitations on the phones must be performed only by the manufacturer or its authorized agent. The user may not make any changes and/or repairs expect as specifically noted in this manual. Therefore, note that unauthorized alternations or repair may affect the regulatory status of the system and may void any remaining warranty.

1. INTRODUCTION

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

- 7 -

2.1 System Overview

2. PERFORMANCE

Item Specification

Shape GSM900/1800/1900 and WCDMA2100 - Bar type Handset

Size 99.8 X 58 X 12.9 mm

Weight Under 92.5g (with 1050mAh Battery)

Power 3.7 V normal, 1050 mAh Li-Polymer

Talk Time Over 100 min (WCDMA, Tx=-23 dBm, Voice)

(with 800mAh) Over 150 min (GSM, Tx=Level 5, Voice)

Standby Time Over 300 Hrs (WCDMA, DRX=1.28)

(with 800mAh) Over 400 Hrs (GSM, Paging period=9)

Antenna Internal type

LCD Main 2.8” 262K 240 X 320 pixel (TFT)

LCD Backlight White LED Back Light

Camera Auto Focus - 2.0 Mega pixel (CMOS) + VGA Video Call Camera

Vibrator Yes (Coin Type)

LED Indicator Yes

MIC Yes

Receiver Yes

Earphone Jack Yes (18 pin)

Connectivity Bluetooth, USB

Volume Key Push Type(+, -)

External Memory Yes

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

- 11 -

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

- 13 -

4) 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) KS20 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) KS20 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 4.00 mA Under 600 mA Under 800mA

(DRX=1.28) (Tx=23dBm) (Tx=23dBm)

Under 3.00 mA Under 350 mA

GSM Paging=9 period (PCL=5)

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

Stand by Voice Call VT

WCDMA

Under 2.5 mA Under 330 mA Under 500mA

(DRX=2.56) (Tx=10dBm) (Tx=10dBm)

Under 2.7 mA Under 270 mA

GSM

Paging=5 period (PCL=7)

LGE Internal Use Only

2.6 Battery BAR

2. PERFORMANCE

- 15 -

Indication Standby

Bar 4 100% ~ 76%

Bar 4 → 3 75%

Bar 3 → 2 50%

Bar 2 → 1 25%

Bar 1 → Empty 5%

Low Voltage, 10%

Warning message+ Blinking 5%

Power Off 3.20 ± 0.05V / 0%

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 : 900 mA

• Normal Battery Capacity : 1050 mAh

• Charging Time : Max 2.5 hours (except for trickle charging time)

• Full charging indication current (charging icon stop current) : 60 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 2 ± 3 dB

Max -13 dB

3 Side Tone Masking Rating (STMR) Min 23 dB

4 Echo Loss (EL) Min 46 dB

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

6 Idle Noise-Receiving (INR)

Nor

Under -54 dBPA

Max

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 KS20 supports UMTS-2100, GSM-900, DCS-1800, and PCS-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 upconversion followed by an offset phase-locked loop that translates the GMSK-modulated or 8-PSK-modulated signal to RF.

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

3. TECHNICAL BRIEF

[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 KS20 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 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 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 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 PAs. The high- and low-band UMTS RF transmit signals emerge from the RTR6275 transceiver.

In the GSM receive path, the received RF signals are applied through their bandpass filters and downconverted 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/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

KS20 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. TECHNICAL BRIEF

- 18 -

LGE Internal Use Only

3. TECHNICAL BRIEF

- 19 -

3.2 GSM Mode

3.2.1 GSM Receiver

The Dual-mode KS20’s receiver functions are split between the three RFICs as follows:

• GSM-900, DCS-1800, and PCS-1900 UMTS-2100 modes bot 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(LSHS-M090U) which includes 3 RX saw filters(GSM900, DCS and PCS). The antenna switch module allows multiple operating bands and modes to share the same antenna. In KS20, 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, PCS-1900 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. 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.

ANT_SEL0 ANT_SEL1 ANT_SEL2

GSM 850/GSM 900 TX HIGH HIGH LOW

GSM 1800/GSM 1900 TX HIGH LOW LOW

GSM 850 RX - - -

GSM 900 RX LOW LOW LOW

GSM 1800 RX LOW LOW LOW

GSM 1900 RX LOW LOW HIGH

WCDMA HIGH LOW HIGH

[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). 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 or 8-PSK processing. These filter circuits include DC offset corrections. The filter outputs are buffered and passed on to the MSM7200 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. 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 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

18Ω

300Ω300Ω

18Ω

300Ω300Ω

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 RFto-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 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 upconverter 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 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 RTR6275 IC design achieves this without allowing FVCO 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/EDGE and UMTS band 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 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 (U503: ACPM-7381)

The UMTS PA output power is monitored by l power detector circuits(U500 : RTR6275). This detector voltage can be used for transmitter calibration and monitor to meet RF system specification.

3. TECHNICAL BRIEF

- 25 -

[Figure 1.5] WCDMA PAM, Duplexer, Coupler

(1608)

10dB

SMPY0015501

As close as possible

20dB

C565 100p

1nH

L520

C554

33p

C561

C560

33p

FL503

ANT

PGNDRX

1 2

SDMY0001301

ACMD-7602

C564

L522

4.7nH

100p

C557

C566 100p

L523

10nH

220p

C556

2.7nH

L521

L524

10nH

C559

33p

C553

33p

R520

VPWR

33p

C558

R521 91

C563

1.5p

R518

VMODE0

VMODE1

U503ACPM-7381

GND1

GND2

GND3

PGND

RFIN

RFOUT

VCC1

110

VCC2

VEN

10u

C555

EFCH1950TDF1

G12G2

R519

FL504

U502

SCDY0003402

50OHM

COUP IN

OUT

PWR_DET

RX_WCDMA_2100

WCDMA_PA_ON

WCDMA_PA_R0

WCDMA_2100_TX_OUT

LGE Internal Use Only

Only for training and service purposes

3.5.2 VCTCXO (X500 : TG-5010LH (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 MSM7200 IC. The oscillator frequency is controlled by the MSM7200 IC.s 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 PM7540 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 PM7540 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 MSM7200 IC require a reference voltage for proper operation and sufficient accuracy. Connecting the PM7540 IC REF_OUT directly to the MSM6275 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 (FL500 : LSHS-M090UE)

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[75], GPIO[74], and GPIO[731]). These GPIOs are programmed to be ANT_SEL0, ANT_SEL1, and ANT_SEL2) respectively.

3. TECHNICAL BRIEF

- 26 -

[Table 1.2] Front End Module control logic

ANT_SEL0 ANT_SEL1 ANT_SEL2

GSM 850/GSM 900 TX HIGH HIGH LOW

GSM 1800/GSM 1900 TX HIGH LOW LOW

GSM 850 RX - - -

GSM 900 RX LOW LOW LOW

GSM 1800 RX LOW LOW LOW

GSM 1900 RX LOW LOW HIGH

WCDMA HIGH LOW HIGH

LGE Internal Use Only

3. TECHNICAL BRIEF

- 27 -

3.5.4 PMIC Functional Block Diagram (U304 : PM7540)

• Complete power management, housekeeping, and user interface functions for wireless devices (CDMA, non-CDMA handsets, and PDAs)

• 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 USB-OTG

- Four buck (step-down), switched-mode power supplies for efficiently generating MSMC1, MSMC2, MSME, and PA supply voltages

- Supports dynamic voltage scaling (DVS) for MSMC1, MSMC2, and PA outputs

- 18 low-dropout regulator circuits with programmable output voltages, implemented using three different current ratings: 300 mA (four), 150 mA (ten), and 50 mA (four). These can be used to power MSMA, MSMP, MSME2, MMC, RFRX1, RFRX2, RFTX, TCXO, SYNT, RUIM1, RUIM2, USB, WLAN, MDDI, CAM, BT, AUX1, and AUX2 circuits.

- One MIC bias regulator circuit

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

- Low power mode available on most regulators

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

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

- Analog multiplexer selects from five internal and up to 28 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: a 32.768 kHz off-chip crystal and an on-chip RC assure 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

- Control TCXO warm-up and synchronize, deglitch, and buffer the TCXO signal

- TCXO buffer control for optimal QPH/catnap timing

- Multistage 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

LGE Internal Use Only

Only for training and service purposes

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

- Two-channel speaker driver with programmable gain, turn-on time, and muting; configurable inputs and outputs capable of stereo or mono operation (drives external 8-Ω speakers with volume controlled 500 mW, each channel)

- Video (TV) amplifier allows use as a camcorder or for slide presentations

• IC-level interfaces

- Configurable SBI (three-wire or single-wire) for efficient initialization, status, and control

- Supports MSM interrupt processing with an internal interrupt manager

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

- Dedicated circuits for controlled poweron sequencing, including the MSM device's reset signal

- Several events continuously monitored for triggering poweron/poweroff 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

- Two sets of RUIM level translators enable MSM device interfacing with external modules

• 22 multipurpose pins that can be configured as digital or analog I/Os, bidirectional I/Os, or current sinks; default functions support the two sets of RUIM level translators, poweron circuits, analog multiplexer inputs, an LED driver, and a selectable reference voltage output.

• Highly integrated functionality in a small package - 137-pin CSP with a several center ground pins for electrical ground, mechanical stability, and thermal relief

3. TECHNICAL BRIEF

- 28 -

[Figure 1.6] MSM7200 Interface

LGE Internal Use Only

3. TECHNICAL BRIEF

- 29 -

[Figure1.7] PM7540 Block Diagram

LGE Internal Use Only

Only for training and service purposes

3.5.5. GSM PAM (U501:TQM7M5003)

The TQM7M5003 is an extremely small (7 x 7 mm), GSM/EDGE PAM for handset applications. This module has been optimized for excellent EDGE efficiency and Pout in a Polar Loop environment at EDGE class E2+ operation while maintaining high GSM/GPRS efficiency. The small size and high performance is achieved with high-reliability 3rdgeneration InGaP HBT technology. With 50Ω and output, no external matching or bias components are required. The module incorporates two highly-integrated InGaP power amplifier die with a CMOS controller. Each amplifier has three gain stages with on-die inter-stage matching implemented with a high Q passives technology for optimal performance. The CMOS controller implements a fully integrated power control within the module for GSM operations, and serves as the AM/AM path in EDGE operations. This eliminates the need for any external couplers, power detectors, current sensing etc., to assure the output power level. The module has Tx enable and band select inputs. Module construction is a low-profile overmolded landgrid array on laminate.

3. TECHNICAL BRIEF

- 30 -

[Figure 1. 8] GSM PAM Schematic

(1608)

MODE

SFSY0030201

TQM7M5008

LOW

3 dB

GSM_PA_BAND

GSM

3 dB

DCS/PCS

HIGH

GND6

GND7

GND8

GSM_IN

GSM_OUT

TX_EN

VBATT

VCC

VRAMP

TQM7M5008

U501

DCS_PCS_IN

DCS_PCS_OUT

GND1

GND2

GND3

GND4

GND5

33p

C540

R513

300

2.2K

R510

R511

4.7p

C539

L514

12nH

6.8nH

L513

C534 22u

VBAT

100p

C533

15p

C541

R512

300

FL501

EFCH897MTDB1

G12G2

L512

2.2nH

300

R516

R514

300

R515

68p

C538

GSM_PA_BAND

GSM_PA_EN

DCS_PCS_TX

GSM_PA_RAMP

GSM_TX

LGE Internal Use Only

3. TECHNICAL BRIEF

- 31 -

3.5.6 UMTS Duplexer(FL503: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 KS20 typical losses : UMTS2100_ Tx = 1.28 dB, UMTS2100_ Rx = 1.46 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 46.7 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 51.7dB.

• 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.

LGE Internal Use Only

Only for training and service purposes

3.5.7 UMTS Rx RF filter (FL502 : EFCH2140TDE1)

• Frequency range : 2110 ~ 2170MHz An RF filter is located between the UMTS LNA and mixer. Insertion loss is important, but not as critical as losses before the LNA. The most important parameters of this component include:

• Out-of-band rejection or attenuation levels, usually specified to meet these conditions:

- Far out-of-band signals - ranging from DC up to the first band of particular concern and from the last band of particular concern to beyond three times the highest passband frequency.

- Tx-band leakage - the transmitter channel power, although attenuated by the duplexer, still presents a cross-modulation threat in combination with Rx-band jammers. The RF filter must provide rejection of this Tx-band leakage.

- Other frequencies of particular concern . bands known to include other wireless transmitters that may deliver significant power levels to the receiver input.

3. TECHNICAL BRIEF

- 32 -

[Table 1.3] WCDMA Rx SAW Filter Specification

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