LG CX800 Service Manual

CDMA PORTABLE CELLULAR PHONE

LG- CX800

SERVICE MANUAL

Dual-band CDMA /GPS

[PCS/Cellular CDMA/GPS]

CDMA Mobile Phone

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General Introduction

CHAPTER 1. System Introduction

CHAPTER 2. NAM Input Method

CHAPTER 3. Circuit Description

CHAPTER 4. Trouble Shooting

CONTENTS

CHAPTER 5. Safety

CHAPTER 6. Glossary

Appendix

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CHAPTER 1. System Introduction

1. Specification

1.1 General Specification

1.1.1 Transmit/Receive Frequency Interval

1) CELLULAR : 70MHz

2) PCS : 140 MHz

1.1.2 Number of Channels (Channel Bandwidth)

1) CELLULAR : 20 Channels

2) PCS : 48 Channels

1.1.3 Operating Voltage : DC 3.2~4.1V

1.1.4 Battery Power Consumption : DC 3.7V

SLEEP IDLE MAX POWER

CELLULAR

PCS

1.1.5 Operating Temperature : -30°C ~ +60°C

1.1.6 Frequency Stability

1) CDMA : ±0.5PPM

2) PCS : ±0.1PPM

1.1.7 Antenna : Fixed Type, 50 Ω

1.1.8 Size and Weight

1) Size : 97.8(H) * 48(W) * 15.2(D) mm

2) Weight : 110 g (Approximately with standard battery)

1.1.9 Channel Spacing

1) CELLULAR : 1.25MHz

2) PCS : 1.25 MHz

1.5 mA 110 ~ 120mA 700 mA (24 dBm)

1.5 mA 120 ~ 130 mA 700 mA (24 dBm)

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1.1.10 Battery Type, Capacity and Operating Time.

Unit = Hours : Minutes

Standard (800mAh)

CELLULAR

Standby Time

PCS

CELLULAR

Talk time

PCS

1.2 Receive Specification

1.2.1 Frequency Range

1) CELLULAR : 869 MHz ~ 894 MHz

2) PCS : 1930 MHz ~ 1990 MHz

3) GPS : 1575.42 MHz

1.2.2 Local Oscillating Frequency Range :

1) CELLULAR : 3476 MHz ~ 3576 MHz

2) PCS : 3860 MHz ∼ 3980 MHz

3) GPS : 3150.84 MHz

160 Hrs (Slotted mode 2, sector

pwr :-75dBm)

160 Hrs (Slotted mode 2, sector

pwr :-75dBm) 144 minute (Rx Power -92dBm, Half rate) 144 minute (Rx Power -92dBm, Half rate)

1.2.3 Sensitivity

1) CELLULAR : -104 dBm (C/N 12dB or more)

2) PCS : -104 dBm (C/N 12dB or more)

3) GPS : -148.5 dBm (w/o SA), -152 dBm (w/SA)

1.2.4 Selectivity

1) CELLULAR : 3dB C/N Degration (With Fch±1.25 KHz : -30dBm)

2) PCS : 3dB C/N Degration (With Fch±1.25 KHz : -30dBm)

1.2.5 Interference Rejection

1) Single Tone : -30dBm at 900 kHz (CELLULAR), -30dBm at 1.25MHz(PCS)

2) Two Tone : -43dBm at 900 kHz & 1700kHz(CELLULAR), -43dBm at 1.25 MHz & 2.05 MHz

1.2.6 Spurious Wave Suppression : Maximum of -80dB

1.2.7 CDMA Input Signal Range

Dynamic area of more than -104~ -25 dB: 79dB at the 1.23MHz band.

z

Transmit Band : below –60dBm

z

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Receive Band : below –80dBm

z

1.3 Transmit Specification

1.3.1 Frequency Range

1) CELLULAR : 824MHz ~ 849MHz

2) PCS : 1850 MHz ~ 1910 MHz

1.3.2 Output Power

1) CELLULAR : 0.224 W

2) PCS: 0.224 W

1.3.3 CDMA TX Frequency Deviation :

1) CELLULAR: +300Hz or less

2) PCS: ± 150Hz

1.3.4 CDMA TX Conducted Spurious Emissions

1) CELLULAR : 900kHz : - 42 dBc/30kHz below

1.98MHz : - 54 dBc/30kHz below

2) PCS : -42 dBc / 30KHz below

1.3.5 CDMA Minimum TX Power Control

1) CELLULAR : - 50dBm below

2) PCS: -50dBm below

1.4 MS (Mobile Station) Transmitter Frequency

1.4.1 CELLULAR mode

Ch # Center Freq. (MHz) Ch # Center Freq. (MHz)

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1011

824.640

404

837.120 29 70

111 152 193 234 275 316 363

825.870

827.100

828.330

829.560

830.790

832.020

833.250

834.480

835.890

445 486 527 568 609 650 697 738 779

838.350

839.580

840.810

842.040

843.270

844.500

845.910

847.140

848.370

1.4.2 PCS mode

Ch # Center Freq (MHz) Ch # Center Freq (MHz) Ch # Center Freq (MHz)

25 1851.25 425 1871.25 825 1891.25 50 1852.50 450 1872.50 850 1892.50

75 1853.75 475 1873.75 875 1893.75 100 1855.00 500 1875.00 900 1895.00 125 1856.25 525 1876.25 925 1896.25 150 1857.50 550 1877.50 950 1897.50 175 1858.75 575 1878.75 975 1898.75 200 1860.00 600 1880.00 1000 1900.00 225 1861.25 625 1881.25 1025 1901.25 250 1862.50 650 1882.50 1050 1902.50 275 1863.75 675 1883.75 1075 1903.75 300 1865.00 700 1885.00 1100 1905.00 325 1866.25 725 1886.25 1125 1906.25 350 1867.50 750 1887.50 1150 1907.50 375 1868.75 775 1888.75 1175 1908.75

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1.5

MS (Mobile Station) Receiver Frequency

1.5.1 CELLULAR mode

Ch. # Center Freq. (MHz) Ch. # Center Freq. (MHz)

1011

29 70

111

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869.640

870.870

872.100

873.330

404 445 486 527

882.120

883.350

884.580

885.810

152

874.560

568

887.040 193 234 275 316 363

1.5.2 PCS mode

Ch # Center Freq (MHz) Ch # Center Freq (MHz) Ch # Center Freq (MHz)

25 1931.25 425 1951.25 825 1971.25 50 1932.50 450 1952.50 850 1972.50

75 1933.75 475 1953.75 875 1973.75 100 1935.00 500 1955.00 900 1975.00 125 1936.25 525 1956.25 925 1976.25

875.790

877.020

878.250

879.480

880.890

609 650 697 738 779

888.270

889.500

890.910

892.140

893.370

150 1937.50 550 1957.50 950 1977.50 175 1938.75 575 1958.75 975 1978.75 200 1940.00 600 1960.00 1000 1980.00 225 1941.25 625 1961.25 1025 1981.25 250 1942.50 650 1962.50 1050 1982.50 275 1943.75 675 1963.75 1075 1983.75 300 1945.00 700 1965.00 1100 1985.00 325 1946.25 725 1966.25 1125 1986.25 350 1947.50 750 1967.50 1150 1987.50 375 1948.75 775 1968.75 1175 1988.75

1.5.3 GPS mode

- Center Freq. : 1575.42MHz

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1.6 AC Adapter : See Appendix

1.7 Cigarret Lighter Adapter : See Appendix

LG Electronics Inc.

1.8 Portable Hands-Free Kit : See Appendix

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2. Installation

2.1 Installing a Battery Pack

1) The Battery pack is keyed so it can only fit one way. Align the groove in the battery pack with the rail on the back of the phone until the battery pack rests flush with the back of the phone.

2) Slide the battery pack forward until you hear a “click”, which locks the battery in place.

2.2 For Adapter Use

1) Plug the adapter into a wall outlet. The adapter can be operated from a 110V source. When AC power is connected to the adapter.

2) Insert the adapter jack into the phone with the installed battery pack.

2.3 For Mobile Mount

2.3.1 Installation Position

In order to reduce echo sound when using the Hands-Free Kit, make sure that the speaker and microphone are

not facing each other and keep microphone a generous distance from the speaker.

2.3.2 Interface Box

Choose an appropriate flat surface ( somewhere under the dash on the passenger side is preferred ) and mount

the IB bracket with the four self-tapping screws provided. Clip the IB into the IB bracket.

2.3.3. Microphone Installation

Install the microphone either by clipping I onto the sunvisor (driver’s side) or by attaching it to door post

(driver’s side), using a velcno adhesive tape (not included).

2.3.4 Cable Connections

2.3.5

Power and Ignition Cables

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CHAPTER 2. NAM Input Method

(Inputting of telephone numbers included)

1. NAM Program Method and Telephone Number Inputting Method

1. 1 Check ESN (Read only)

Idle Screen Enter ‘MENU’, And Press “#” Press “9”

Î Î

Press “1” You can see ESN and PHONE NUMBER.

Î

1.2 Write PHONE NUMBER.

Idle Screen Press “##000000#” Press “2”

Î Î

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Enter PHONE NUMBER(MDN) Enter PHONE NUMBER(MSID) And Press “OK”. And Press “OK” Press “3” Phone is reset.

Î Î Î

Powering Off

CHAPTER 3. Circuit Description

1. RF Transmit/Receive Part

1.1 Overview

The Tx and Rx part employs the Direct-Conversion system. The Tx and Rx frequencies are respectively

824.04~848.97 and 869.04~893.97 for cellular and 1850~1910 and 1930~1990 for PCS. The block diagram is

shown in [Figure 1-1]. RF signals received through the antenna are seperated by the Quintplexer.

RF Signal fed into Skyworks RX MCM(SKY 74609) through the Quintplexer. In RX MCM, the IF signal is changed into baseband signal directly. Then, this signal is changed into digital signal by the analog to digital converter (ADC, A/D Converter), and the digital circuit part of the MSM(Mobile Station Modem) 6500 processes the data from ADC. The digital processing part is a demodulator.

In the case of transmission, TX MCM(SKY 74709) receives OQPSK-modulated anlaog signal from the MSM6500. The TX MCM connects directly with MSM6500 using an analog baseband interface. In TX MCM, the baseband quadrature signals are upconverted to the Cellular or PCS frequency bands and amplified to provide signal drive capability to the pow er amp.

After that, the RF signal is amplified by the TX MCM in order to have enough power for radiation. Finally, the RF signal is sent out to the cell site via the antenna after going through the Quintplexer.

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Antenna

B/T Chip

B/T Chip Antenna

Antenna

Quint-

plexer

GPS

GPS LNA

LNA

BT_VCTCXO

Bluetooth RF

VCTCXO 19.2MHz

INNER CHG

BATTERY

+2.9V_Rx_LDO

HDET

SKY

74609

RX

SKY

74609

TX

RF Interface

SKY 74709

SKY 74609

GPS

GPS BPF

BPF

MSM6500

Bluetooth

Bluetooth Baseband

Baseband

Baseband Processor

Processor

PLL

HK ADC

Rx

ADCs

RF

Interface

TX

DACs

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AUX

SBI

MSM6500

Mobile Station Modem

gpsOne

Processor

CDMA

Processor

DFM

Processor

JTAG Interfaces

SKY 74609

UART1

UART2

UART3/USB

CAMIF

ARM9

ARM9 TDMI

TDMI

Memory

Controller

General-

GeneralPurpose

Purpose

Interface

Vocoder

EVRC

13k

13k MP4

MP4

MIDI

QDSP4000

Integrated

CODEC

MODE Select

Interface

ETM

Data Comm

DM

USB

Transceiver

LDO

Camera module

Camera module (1.3M C-MOS)

(1.3M C-MOS)

Microprocessor Bus

Address/Data

General-Purpose Interface Bus

1 2 3

1 2 3 4 5 6

4 5 6

Keypad input

2

4 5 6 7 8 9

7 8 9

7 8 9 * #0

* #0

OK

OKOK

Audio AMP

EAR

MIC

Digital Test Bus JTAG

TX,RX I Q

SBI,AUX SBI

PC

Connectivity

Test/Debug

System

Memory

NAND Flash(2Gb)

LP-SDRAM(512Mb)

KEYPAD, BEZEL ,

SIIDEKEY

Touch Key PAD

Speaker

External

External EAR/MIC

EAR/MIC

LCD

MSM

MSM 6500

6500

Peripheral Circuits

[Figure 1-1] Block Diagram Of CX800

1.2 Description of Receive Part Circuit

LG Electronics Inc.

1.2.1 Quintplexer (U105)

The ACFM-7101 is a Quintplexer that combines a US PCS duplexer, a cellular band duplexer and a GPS band filter into a single, miniature package with a single antenna port

The main function of Quintplexer(ACFM-7101) is to prohibit the other band signals from flowing into the one band circuit and vice versa. RF designer can use common tri-band antenna regardless of frequency band (800, 1575 and 1900 MHz). The specification of CX800 Quintplexer is described below:

.

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1.2.2

The SKY74609 receiver is a highly integrated device for tri-band, dual-mode Code Division Multiple Access (CDMA) handsets with Global Positioning System (GPS) capability. The SKY74609 supports CDMA phones in the cellular CDMA, Personal Communications System (PCS), and GPS modes. The device requires a minimum number of external components to complete a CDMA radio subsystem. Included on-chip are the down converter, base band filters with auto-tuning loop, UHF Voltage Controlled Oscillator (VCO), RF Phase Locked Loop(PLL),and DC Offset Compensation (DCOC).External components needed for operation include matching networks for differential mixer inputs and differential GPS Low Noise Amplifier (LNA) inputs, CDMA/PCS Surface Acoustic Wave (SAW) filters, three bias resistors for accurate bias control over process variation, and two high tolerance load resistors for In- Phase and Quadrature (I/Q) baseband output. The SKY74609 output is a dual-channel, fully differential analog signal at the baseband. Both channels maintain a quadrature phase relationship with each other.

RX MCM (SKY74609: U104)

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1.2.3 TX MCM (SKY74709: U103)

The SKY74709 transmitter is a highly integrated device designed for dual-band, single-mode CDMA handsets in the cellular CDMA and Personal Communications System (PCS) modes. The SKY74709 includes interstage transmit Surface Acoustic Wave (SAW) filters and separate CDMA and PCS Gallium Arsenide (GaAs) Microwave Monolithic Integrated Circuit (MMIC) Power Amplifiers (PAs). The device meets the stringent CDMA linearity requirements up to 28 dBm output power. The incoming CDMA baseband signal is upconverted to the desired RF frequency by the In-Phase and Quadrature (I/Q) modulator and amplified by the appropriate PA driver stage to provide variable outpu t p ower. The signal is filtered by an interstage transmit SAW filter and sent to the respective PA to obtain the final rated power. The only external components needed to complete a CDMA radio subsystem are supply bypass capacitors and filtering capacitors at the I/Q inputs. The required Phase Lock Loop (PLL) filter and bias resistors have been included on-chip. The state of the PAs is controlled by the SKY74709, which eliminates the need for external switches to enable/disable the PAs and control their gain. The SKY74709 is designed to operate within a supply voltage range of 3.2 V to 4.2 V. Together with the SKY74609 receiver, the SKY74709 transmitter forms Skyworks Tri-Band, Dual-Mode CDMA RF Subsystem. This subsystem is compliant with the IS-95, CDMA2000, and E-911standards.

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1.2.4 GPS LAN(U102)

The characteristics of Low Noise Amplifier (LNA) are low noise figure, high gain, high intercept point and high reverse isolation. The frequency selectivity characteristic of mobile phone is mostly determined by LNA.

The specification of CX800 GPS LNA is described below

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Parameter GPS Band Units

Gain

Noise Figure

1dB compression point

IIP3

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17.7 dB

0.6 dB

14.4 dBm

6.5 dBm

1.2.5 GPS Rx RF SAW FILTER(F100)

The main function of GPS Rx RF SAW filter is to attenuate mobile phone spurious frequency, attenuate noise

amplified by the GPS LNA and suppress second harmonic originating in the GPS LNA.

1.3 Description of Frequency Synthesizer Circuit

1.3.1 Voltage Control Temperature Compensation Crystal Oscillator (VCTCXO, F101)

The temperature variation of mobile phone can be compensated by VCTCXO. The reference frequency of a mobile phone is 19.2 MHz. The receiver frequency tuning signals called TRK_LO_ADJ from MSM as 0.5 V~2.5 V DC via R and C filter in order to generate the reference frequency of 19.2 MHz and input it into the frequency synthesizer. Frequency stability depending on temperature is ±2.0 ppm.

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2. Digital/Voice Processing Part

2.1 Overview

The digital/voice processing part processes the user's commands and processes all the digital and voice signal processing in order to operate in the phone. The digital/voice processing part is made up of a keypad/LCD, receptacle part, voice processing part, mobile station modem part, memory part, and power supply part.

2.2 Configuration

2.2.1 Keypad/LCD and Receptacle Part

This is used to transmit keypad signals to MSM6500. It is made up of a keypad backlight part that illuminates the keypad, LCD part that displays the operation status onto the screen, and a receptacle that receives and sends out voice and data with external sources.

2.2.2 Voice Processing Part

The voice processing part is made up of an audio codec used to convert MIC signals into digital voice signals and digital voice signals into analog voice signals, amplifying part for amplifying the voice signals and sending them to the ear piece, amplifying part that amplifies ringer signals coming out from MSM6500, and amplifying part that amplifies signals coming out from MIC and transferring them to the audio processor.

2.2.3 MSM (Mobile Station Modem) 6500 Part

MSM is the core elements of CDMA terminal and carries out the functions of CPU, encoder, interleaver, deinterleaver, Viterbi decoder, Mod/Demod, and vocoder.

2.2.4 Memory Part

The memory part is made up of a flash memory, SRAM for storing data. Our memory is consist of 2G NAND flahs memory and 512 SRAM.

2.2.5 Power Supply Part

The power supply part is made up of circuits for generating various types of power, used for the digital/voice processing part.

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2.3 Circuit Description

2.3.1 Keypad/LCD and Receptacle Part

Once the keypad is pressed, the key signals are sent out to MSM6500 for processing. In addition, when the key is pressed, the keypad lights up through the use of EL. The terminal status and operation are displayed on

the screen for the user with the characters and icons on the LCD.

Moreover, it exchanges audio signals and data with external sources through the receptacle, and then receives power from the battery or external batteries.

2.3.2 Audio Processing Part

MIC signals are amplified through OP AMP, inputted into the audio codec(included in MSM6500) and converted into digital signals. Oppositely, digital audio signals are converted into analog signals after going through the audio codec. These signals are amplified at the audio amplifier and transmitted to the ear-piece. The signals from MSM6500 activate the ringer by using signals generated in the timer in MSM6500.

2.3.3 MSM Part

MSM6500 is the core element of CDMA system terminal that includes ARM926EJ-S microprocessor core. It supports both CDMA and Digital FM, operating in both the cellular and PCS spectrums. The subsystems within the MSM6500 include a CDMA processor, a DFM processor, a multi-standard Vocoder, an integrated CODEC with earpiece and microphone amplifiers, general-purpose ADC for subsystem monitoring, an ARM926EJ-S microprocessor, and both Universal Serial Bus(USB) and an RS-232 serial interfaces supporting forward and reverse link data communications of 307.2 Kbps simultaneously. And it also contains complete digital modulation and demodulation systems for CDMA standards, as specified in IS-95-A/B/C. In MSM, coded symbols are interleaved in order to cope with multi-path fading. Each data channel is scrambled by the long code PN sequence of the user in order to ensure the con fidentiality of calls. Moreover, binary quadr ature codes are used based on walsh functions in order to discern each channel. Data created thus are 4-phase modulated by one pair of Pilot PN code and they are used to create I and Q data. When received, I and Q data are demodulated into symbols by the demodulator, and then de-interleaved in reverse to the case of transmission. Then, the errors of data received from viterbi decoder are detected and corrected. They are voice-decoded at the vocoder in order to output digital voice data.

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LCD

Flash Memory

Earpiece

Mic

Keypad

MSM6500

Processor

Audio

Ringer

Power Supply

[Figure 2-2] Block Diagram of Digital/Voice Processing Part

SRAM

CAMERA MODULE

Receptacle

2.3.4 Memory Part

MCP contents 2 Gbits flash memory and 512 Mbits Static RAM. In the Flash Memory part of MCP are programs used for terminal operation. The programs can be changed through down loading after the assembling of terminals. On the SRAM data generated during the terminal operation are stored temporarily.

2.3.5 Power Supply Part

When the battery voltage (+3.7V) is fed and the PWR key of keypad is pressed, the power-up circuitry in Power on & off part is activated by the PWR_ON_SW signal, and then the LDO regulators for MSM are operated and +1.4V_MSMC, +1.85V_MSMP1,+2.6V_MSMP2, and +2.6V_MSMA are generated.

The Rx part regulator (+2.85V_RX) is operated by the control signal of SLEEP/ from MSM6500

The Tx part regulator (+3.1V_TX) is operated by the control signal of IDLE/ from MSM6500.

The Camera part regulators(+1.5V_CAM_VDD,+2.8V_A_SENSOR,+2.8V_D_SENSOR) are operated by the control signal of CAMERA_EN/from MSM6500

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2.3.6 Logic Part

The logic part consists of internal CPU of MSM, RAM(MCP). The MSM6500 receives TCXO (=19.2MHz) from U104 and controls the phone in both CDMA and FM modes. The major components are as follows:

z

The ARM926EJ-S microprocessor includes a 3 stage pipelined RISC architecture, both 32-bit ARM and 16-bit THUMB instruction sets, a 32-bit address bus, and a 32-bit internal data bus. It has a high performance and low power consumption.

CPU

z

Flash ROM is used to store the terminal’s program. Using the down-loading program, the program can be changed even after the terminal is fully assembled.

SRAM is used to store the internal flag information, call processing data, and timer data.

z

For key recognition, key matrix is setup using KYPD[1][3][5][7][9][11][13][15][17][19][21] signal from MSM. The keypad lights up through the use of EL for easy operation in the dark.

MCP

KEYPAD

LG Electronics Inc.

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CHAPTER 4. Trouble Shooting

4.1 Rx Part Trouble

4.1.1 When Rx power isn’t enough

Test Point

Figure 4.1-1

CHECK POINTS OF RX PART

1

Checking Flow

START

Rx TEST SETUP(HHP)

- Test Channel : DCN(400) or PCS (600)

E5515C Setup

- CH : DCN(400) or PCS(600)

- Sector Power : -30 dBm Spectrum Analyzer Setting Oscilloscope Setting

1. Check

PMIC Circuit

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4

3

5

2

2. Check

VCTCXO Circuit

3. Check

Control Signal

4. Check

Duplexer, Mobile SW

5. Check

Rx I/Q data

√ RedownloadSW, CAL

4.1.2 Checking Regulator Circuit

Test Point

U302 Pin 1

PS_Hold

Circuit Diagram

Figure 4.1-3 RX PART CIRCUIT OF MAX1829PMIC

U302 Pin10 +2.85V_RX

Figure 4.1-2

MAX1829 PMIC

Checking Flow

Check Pin 10 of U302

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Check Pin 10 of U302

+2.85V_Rx OK?

PMIC Circuit is OK See

next Page to check

VCTCXO

No

Pin 10 High?

YesYes

Replace U302

No

Changing Board

4.1.3 Checking VCTCXO Circuit

Test Point

F101 Pin4

+2.8V_TCXO

F101 Pin3

TCXO

Figure 4.2-6 VCTCXO

Circuit Diagram

Check F101 Pin 3

Check F101 Pin 4

Checking Flow

19.2MHz OK?

No

+2.85V OK?

No

Check U304

Yes

VCTCXO Circuit is Ok See next Page to check Quintplexer

Changing F101

Figure 4.2-7 VCTCXO CIRCUIT

Waveform

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Figure 4.1-6 TCXO OUT WAVEFORM Figure 4.1-7 +2.8 5V _TCX O WAV EF ORM

LG CX800 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual