LG KV800 Service Manual

CDMA Mobile Subscriber Unit

LG-KV800

SERVICE MANUAL

Dual BAND, Dual MODE

[GPS/CELLULAR]

CDMA MOBILE PHONE

Only for training and service purpose.

1

Table of Contents

General Introduction

CHAPTER 1. System Introduction

1.1. System Introduction……………..……..2

1.2. Features and Advantages of CDMA

Mobile Phone (For AMPS as well)..….3

1.3. Structure and Functions of dual-band

CDMA Mobile Phone……………...….6

1.4. Specification……………………………7

1.5. Installation…………………………….10

CHPATER 2. NAM Input Method

2.1. NAM Program Method and Telephone

Number Inputting Method……………11

CHAPTER 3. Circuit Description

3.1. RF Transmit/Receive Part…………….12

………...……………...1

4.2.7 Check Coupler & Duplexer &

Diplexer & Mobile S/W…...………41

4.3 Logic part Trouble

4.3.1 Power ON trouble…………………43

4.3.2 Battery Charging trouble………….46

4.3.3 Camera trouble……………………49

4.3.4 LCD trouble………………………52

4.3.5 Speaker trouble……………………55

4.3.6 MIC trouble……………………….58

4.3.7 Headset trouble……………………61

4.3.8 Keypad Backlight trouble…………66

4.3.9 Motor trouble……………………..68

4.3.10 BLUETOOTH trouble…………..71

4.3.11 Touch Sensor trouble……………74

CHAPTER 5. Safety

.....................................77

3.2. Digital/Voice Processing Part…...……17

CHAPTER 4. Trouble Shooting

4.1 Rxpart Trouble

4.1.1 When Rx Power isn't enough…......21

4.1.2 Check Regulator(PMIC) Circuit….22

4.1.3 Check TCXO circuit……………...23

4.1.4 Check Mobile S/W & Diplexer &

Duplexer………………………….24

4.1.5 Check LNA & SAW………………26

4.1.6 Check SBI control Signal………....28

4.1.7 Check Rx I/Q data………………...30

4.2 Tx part Trouble………………………..32

4.2.1 Check Regulator(PMIC) Circuit….33

4.2.2 Check TCXO Circuit……………..34

4.2.3 Check SBI Control Signal………...35

4.2.4 Check RFT6150 Circuit…………..36

CHAPTER 6. Glossary

CHAPTER 7. APPENDIX

7.1 KV800 Block and Circuit diagram…....94

7.1.1 KV800 RF Block diagram……......95

7.1.2 KV800 LOGIC Block diagram.......96

7.1.3 KV800 Main PCB Circuit….......…99

7.1.4.KV800 Sub PCB Circuit….…...104

7.1.5 KV800 RF FPCB..........................106

7.2 KV800 BGA PIN Map……………….107

7.3 KV800 Component Layout...………...112

7.4. KV800 Exploded view……….……...118

7.4.1 KV800 Assy view……….……....119

7.4.2 KV800 Full view………….……..120

7.5 KV800 Part List……………………...121

7.5.1 KV800 Main PCB Part List…..…122

…..…………………80

….……………...93

4.2.5 Check HDET Circuit……………...38

4.2.6 Check PAM Circuit……………….39

Only for training and service purpose.

1

7.5.2 KV800 Sub PCB Part List..……..131

7.5.3 KV800 RF FPCB part list……….135

General Introduction

The LG-KV800 phone has been designed to operate on the latest digital mobile communication technology,

Code Division Multiple Access (CDMA). This CDMA digital technology has greatly enhanced voice clarity and

can provide a variety of advanced features. The LG-KV800 support GPS Mode, we usually call it dual-band

phone.

The CDMA technology adopts DSSS (Direct Sequence Spread Spectrum). This feature of DSSS enables the

phone to keep communication from being crossed and to use one frequency channel by multiple users in the

same specific area, resulting that it increases the capacity 10 times more compared with that in the analog mode

currently used. Soft/Softer Handoff, Hard Handoff, and Dynamic RF power Control technologies are combined

into this phone to reduce the call being interrupted in a middle of talking over the phone. CDMA network

consists of MSO (Mobile Switching Office), BSC (Base Station Controller), BTS (Base station Transmission

System), and MS (Mobile Station). The following table lists some major CDMA Standards.

CDMA Standard Designator Description

Basic air interface TIA/EIA/IS-95-A/B/C

ANSI J-STD-008

Network TIA/EIA/IS-634

TIA/EIA/IS/651

TIA/EIA/IS-41-C

TIA/EIA/IS-124

Service TIA/EIA/IS-96-B

TIA/EIA/IS-99

TIA/EIA/IS-637

TIA/EIA/IS-657

Performance TIA/EIA/IS-97

TIA/EIA/IS-98

ANSI J-STD-018

ANSI J-STD-019

TIA/EIA/IS-125

* TSB –74: Protocol between an IS-95A system and ANSI J-STD-008

Protocol between MS and BTS for Cellular & AMPS

Protocol between MS and BTS for PCS

MAS-BS

PCSC-RS

Intersystem operations

Nom-signaling data comm.

Speech CODEC

Assign data and fax

Short message service

Packet data

Cellular base station

Cellular mobile station

PCS personal station

PCS base station

Speech CODEC

Only for training and service purpose.

1

Chapter 1. System Introduction

1. System Introduction

1.1 CDMA Abstract

The CDMA mobile communication system has a channel hand-off function that is used for collecting the

information on the locations and movements of mobile telephones from the cell site by automatically controlling

several cell site through the setup of data transmission routes, and then enabling one switching system to carry

out the automatic remote adjustment. This is to maintain continuously the call state through the automatic

location confirmation and automatic radio channel conversion when the busy subscriber moves from the service

area of one cell site to that of another by using automatic location confirmation and automatic radio channel

conversion functions. The call state can be maintained continuously by the information exchange between

switching systems when the busy subscriber moves from one cellular system area to the other cellular system

area.

In the cellular system, the cell site is a small-sized low output type and utilizes a frequency allocation system

that considers mutual interference, in an effort to enable the re-use of corresponding frequency from a cell site

separated more than a certain distance. The analog cellular systems are classified further into an AMPS system,

E-AMPS System, NMT system, ETACS system, and JTACS system depending on technologies used.

Unlike the time division multiple access (TDMA) or frequency division multiple access (FDMA) used in the

band limited environment, the Code Division Multiple Access (CDMA) system which is one of digital cellular

systems is a multi-access technology under the interference limited environment. It can process more number of

subscribers compared to other systems (TDMA system has the processing capacity three times greater than the

existing FDMA system whereas CDMA system, about 12~15 times of that of the existing system).

CDMA system can be explained as follows; TDMA or CDMA can be used to enable each person to talk

alternately or provide a separate room for each person when two persons desire to talk with each other at the

same time, whereas FDMA can be used to enable one person to talk in soprano, whereas the other in bass (one

of the two talkers can carry out synchronization for hearing in case there is a bandpass filter function in the area

of the hearer). Another available method is to make two persons to sing in different languages at the same time,

space, and frequency when wishing to let the audience hear the singing without being confused. This is the

characteristic of CDMA.

On the other hand, when employing the CDMA technology, each signal has a different pseudo-random binary

sequence used to spread the spectrum of carrier. A great number of CDMA signals share the same frequency

spectrum. In the perspective of frequency area or time area, several CDMA signals are overlapped. Among these

types of signals, only desired signal energy is selected and received through the use of pre-determined binary

sequence; desired signals can be separated, and then received with the correlator used for recovering the

spectrum into its original state. At this time, the spectrums of other signals that have different codes are not

recovered into its original state, and appears as the self-interference of the system.

Only for training and service purpose.

2

1.2. Features and Advantages of CDMA Mobile Phone

1.2.1 Various Types of Diversities

When employing the narrow band modulation (30kHz band) that is the same as the analog FM modulation

system used in the existing cellular system, the multi-paths of radio waves create a serious fading. However, in

the CDMA broadband modulation (1.25MHz band), three types of diversities (time, frequency, and space) are

used to reduce serious fading problems generated from radio channels in order to obtain high-quality calls.

Time diversity can be obtained through the use of code interleaving and error correction code whereas frequency

diversity can be obtained by spreading signal energy to wider frequency band. The fading related to normal

frequency can affect the normal 200~300kHz among signal bands and accordingly, serious effect can be avoided.

Moreover, space diversity (also called path diversity) can be realized with the following three types of methods.

First, it can be obtained by the duplication of cell site receive antenna. Second, it can be obtained through the

use of multi-signal processing device that receives a transmit signal having each different transmission delay

time and then, combines them. Third, it can be obtained through the multiple cell site connection (Soft Handoff)

that connects the mobile station with more than two cell sites at the same time.

1.2.2 Power Control

The CDMA system utilizes the forward (from a base station to mobile stations) and backward (from the mobile

station to the base station) power control in order to increase the call processing capacity and obtain high-quality

calls. In case the originating signals of mobile stations are received by the cell site in the minimum call quality

level (signal to interference) through the use of transmit power control on all the mobile stations, the system

capacity can be maximized. If the signal power of mobile station is received too strong, the performance of that

mobile station is improved. However, because of this, the interference on other mobile stations using the same

channel is increased and accordingly, the call quality of other subscribers is reduced unless the maximum

accommodation capacity is reduced.

In the CDMA system, forward power control, backward open loop power control, and closed loop power control

methods are used. The forward power control is carried out in the cell site to reduce the transmit power on

mobile stations less affected by the multi-path fading and shadow phenomenon and the interference of other cell

sites when the mobile station is not engaged in the call or is relatively nearer to the corresponding cell site. This

is also used to provide additional power to mobile stations having high call error rates, located in bad reception

areas or far away from the cell site.

The backward open loop power control is carried out in a corresponding mobile station; the mobile station

measures power received from the cell site and then, reversely increases/decreases transmit power in order to

compensate channel changes caused by the forward link path loss and terrain characteristics in relation to the

mobile station in the cell site. By doing so, all the mobile transmit signals received by the base station have same

strength.

Moreover, the backward closed loop power control used by the mobile station is performed to control power

using the commands issued out by the cell site. The cell site receives the signal of each corresponding mobile

station and compares this with the pre-set threshold value and then, issues out power increase/decrease

commands to the corresponding mobile station every 1.25msec (800 times per second). By doing so, the gain

tolerance and the different radio propagation loss on the forward/backward link are complemented.

Only for training and service purpose.

3

1.2.3 Voice Encoder and Variable Data Speed

The bi-directional voice service having variable data speed provides voice communication which employs

voice encoder algorithm having power variable data rate between the base station and the mobile station. On the

other hand, the transmit voice encoder performs voice sampling and then, creates encoded voice packets to be

sent out to the receive voice encoder, whereas the receive voice encoder demodulates the received voice packets

into voice samples.

One of the two voice encoders described in the above is selected for use depending on inputted automatic

conditions and message/data; both of them utilize four-stage frames of 9600, 4800, 2400, and 1200 bits per

second for cellular. In addition, this type of variable voice encoder utilizes adaptive threshold values on

selecting required data rate. It is adjusted in accordance with the size of background noise and the data rate is

increased to high rate only when the voice of caller is inputted.

Therefore, background noise is suppressed and high-quality voice transmission is possible under the

environment experiencing serious noise. In addition, in case the caller does not talk, data transmission rate is

reduced so that the transmission is carried out in low energy. This will reduce the interference on other CDMA

signals and as a result, improve system performance (capacity increased by about two times).

1.2.4 Protecting Call Confidentiality

Voice privercy is provided in the CDMA system by means of the private long code mask used for PN spreading.

Voice privacy can ve applied on the traffic channels only. All calls are initiated using the public long code mask

for PN spreading. The mobile station user may request voice privacy during call setup using the origination

message or page response message, and during traffic channel operation using the long code transition request

order.

The Transition to private long code mask will not be performed if authentication is not performed. To initiate a

transition to the private or public long code mask, either the base station or the mobile station sends a long code

transition request order on the traffic channel.

1.2.5 Soft Handoff

A handoff in which the mobile station commences communications with a new base station without interrupting

communications with the old base station. Soft handoff can only be used between CDMA channels having

identical freqeuncy assignments.

1.2.6 Frequency Re-Use and Sector Segmentation

Unlike the existing analog cellular system, the CDMA system can reuse the same frequency at the adjacent cell.

there is no need to prepare a separate frequency plan. Total interference generated on mobile station signals

received from the cell site is the sum of interference generated from other mobile stations in the same cell site

and interference generated from the mobile station of adjacent cell site. That is, each mobile station signal

Only for training and service purpose.

4

generates interference in relation to the signals of all the other mobile stations.

Total interference from all the adjacent cell sites is the ratio of interference from all the cell sites versus total

interference from other mobile stations in the same cell site (about 65%). In the case of directional cell site, one

cell normally uses a 120°sector antenna in order to divide the sector into three. In this case, each antenna is used

only for 1/3 of mobile stations in the cell site and accordingly, interference is reduced by 1/3 on the average and

the capacity that can be supported by the entire system is increased by three times.

1.2.7 Soft Capacity

The subscriber capacity of the CDMA system is flexible depending on the relation between the number of

users and service classes. For example, the system operator can increase the number of channels available for

use during the busy hour despite the drop in call quality. This type of function requires 40% of normal call

channels in the standby mode during the handoff, in an effort to avoid call disconnection resulting from the lack

of channels.

In addition, in the CDMA system, services and service charges are classified further into different classes so that

more transmit power can be allocated to high class service users for easier call set-up; they can also be given

higher priority of using hand-off function than the general users.

Only for training and service purpose.

5

1.3. Structure and Functions of tri-band CDMA Mobile Phone

The hardware structure of CDMA mobile phone is made up of radio frequency (RF) part and logic part. The

RF part is composed of Receiver part (Rx), Transmitter part (Tx) and Local part (LO). For the purpose of

operating on tri-band, It is necessary dual Tx path, tri Rx path, dual PLL and switching system for band

selection. The mobile phone antenna is connected with the diplexer which divide antenna input/output cellular

frequency band (824~894 Mhz) and GPS frequency band(1575.42 MHz). The cellular path is linked with the

cellular duplexer. Duplexer carrys out seperating Rx band and Tx band. The Rx signals from the antenna are

converted into intermediate frequency(IF) band by the frequency synthesizer and frequency down converter.

And then, pass SAW filter which is a band pass filter for removing out image frequency. The IF output signals

that have been filtered is converted into digital signals via Analog-to-Digital Converter (ADC). In front of the

ADC, switching system is required to choose which band path should be open.

The digital signals send to 5 correlators in each CDMA de-modulator. Of these, one is called a searcher whereas

the remaining 4 are called data receivers (fingers). Digitalized IF signals include a great number of call signals

that have been sent out by the adjacent cells. These signals are detected with pseudo-noise sequence (PN

equence).

Signal to interference ratio (C/I) on signals that match the desired PN sequence are increased through this type

of correlation detection process, but other signals obtain processing gain by not increasing the ratio. The carrier

wave of pilot channel from the cell site most adjacently located is demodulated in order to obtain the sequence

of encoded data symbols. During the operation with one cell site, the searcher searches out multi-paths in

accordance with terrain and building reflections. On three data receivers, the most powerful 3 paths are allocated

for the parallel tracing and receiving. Fading resistance can be improved a great deal by obtaining the diversity

combined output for de-modulation. Moreover, the searcher can be used to determine the mostpowerful path

from the cell sites even during the soft handoff between the two cell sites. Moreover, 3 data receivers are

allocated in order to carry out the de-modulation of these paths. Output data that has been demodulated changes

the data string in the combined data row as in the case of original signals(deinterleaving), and then, are

demodulated by the forward error correction decoder which uses the Viterbi algorithm. Mobile station user

information send out from the mobile station to the cell site pass through the digital voice encoder via a mike.

Then, they are encoded and forward errors are corrected through the use of convolution encoder. Then, the order

of code rows is changed in accordance with a certain regulation in order to remove any errors in the interleaver.

Symbols made through the above process are spread after being loaded onto PN carrier waves. At this time, PN

sequence is selected by each address designated in each call.

Signals that have been code spread as above are digital modulated (QPSK) and then, power controlled at the

automatic gain control amplifier (AGC Amp). Then, they are converted into RF band by the frequency

synthesizer synchronizing these signals to proper output frequencies.

Transmit signals obtained pass through the duplexer filter and then, are sent out to the cell site via the antenna.

Only for training and service purpose.

6

1.4. Specification

1.4.1 General Specification

1.4.1.1 Transmit/Receive Frequency Interval :

1) CELLULAR : 45 MHz

1.4.1.2 Number of Channels (Channel Bandwidth)

1) CELLULAR : 20 Channels

1.4.1.3 Operating Voltage : DC 3.3~4.2V

1.4.1.4 Battery Power Consumption : DC 3.7V

SLEEP IDLE MAX POWER

CELLULAR

1.4.1.5 Operating Temperature : -20°C ~ +60°C

2.5 mA 200mA 900 mA (24.2 dBm)

1.4.1.6 Frequency Stability

1) CDMA : ±0.5PPM

1.4.1.7 Antenna : Internal Antenna, 50 Ω

1.4.1.8 Size and Weight

1) Size : 104.0 (H) x 54.4 (W) x 12.85(D) mm (with 900mAh)

2) Weight : 100g (with 900mAh Battery)

1.4.1.9 Channel Spacing

1) CELLULAR : 1.25MHz

1.4.1.10 Battery Type, Capacity and Orerating Time.

Unit = Hours, Minutes

Standard (900mAh)

Standby Time DCN (Slot Cycle 2)

Talk Time DCN (Slot Cycle 2)

Only for training and service purpose.

150Min.(typical duplexer,10dBm output)

7

About 150 Hrs (SCI=2)

1.4.2 Receive Specification

1.4.2.1 Frequency Range

1) CELLULAR : 869.820 MHz ~ 893.190 MHz

2) GPS : 1575.42 MHz

1.4.2.2 Local Oscillating Frequency Range :

1) CELLULAR : 1738.08MHz ~ 1787.94MHz

2) GPS : 3150.84MHz

1.4.2.3 Sensitivity

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

2) GPS : -148.5dBm

1.4.2.4 Selectivity

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

1.4.2.5 Interference Rejection

1) Single Tone : -30dBm at 900 kHz (CELLULAR)

2) Two Tone : -43dBm at 900 kHz & 1700kHz(CELLULAR)

1.4.2.6 Spurious Wave Suppression : Maximum of -80dB

1.4.2.7 CDMA Input Signal Range

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

1.4.3 Transmit Specification

1.4.3.1 Frequency Range

1) CELLULAR : 824.820MHz ~ 848.190MHz

1.4.3.2 Output Power

1) CELLULAR : 0.236W

1.4.3.3 CDMA TX Frequency Deviation :

1) CELLULAR: +300Hz or less

1.4.3.4 CDMA TX Conducted Spurious Emissions

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

1.98MHz : - 54 dBc/30kHz below

Only for training and service purpose.

8

1.4.3.5 CDMA Minimum TX Power Control

1) CELLULAR : - 50dBm below

4.4

1.

MS (Mobile Station) Transmitter Frequency

1.

4.4.1 CELLULAR mode

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

1011

29

70

111

152

193

234

275

316

363

824.640

825.870

827.100

828.330

829.560

830.790

832.020

833.250

834.480

835.890

1.4.5 MS (Mobile Station) Receiver Frequency

1.

4.5.1 CELLULAR mode

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

1011

869.640

404

445

486

527

568

609

650

697

738

779

404

837.120

838.350

839.580

840.810

842.040

843.270

844.500

845.910

847.140

848.370

882.120

29

70

111

152

193

234

275

316

363

1.

4.5.2 GPS mode : 1575.42MHz

1.

4.6 AC Adapter : See Appendix

Only for training and service purpose.

870.870

872.100

873.330

874.560

875.790

877.020

878.250

879.480

880.890

445

486

527

568

609

650

697

738

779

9

883.350

884.580

885.810

887.040

888.270

889.500

890.910

892.140

893.370

1.5. Installation

1.5.1 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.

1.5.2 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.

Red light indicates battery is being charged.. Green light indicates battry is fully charged.

Only for training and service purpose.

10

CHAPTER 2. NAM Input Method

(Inputting of telephone numbers included)

2.1 NAM Programming Method and Telephone Number Input Method

Æ Enter the menu

Æ Press and hold CLR key (center key) for a few seconds and press 159753

Æ You can see following Menu

1 : Service settings

2 : Test Screen

3 : Test Call

4 : Error Screen

5 : Error Delete

6 : Select Vocoder

7 : Test Mode Settings

8 : MRU Settings

9 : A-Key Settings

10 : ADM Verufy

11 : WAP Service Settings

12 : BREW Settings

13 : Data SPD Srttings

14 : MMS Settings

15 : LCD Always On

16 : Exception ReportSys

17 : BIN CRC CHECK

Æ Press 1 : Service Mode to program MIN and NAM

Æ Press a number what you want to edit

Æ Press [edit] to edit, after input, press [OK] to save

Æ To reset the handset, press [END]

Only for training and service purpose.

11

CHAPTER 3. Circuit Description

3.1. RF Transmit/Receive Part

3.1.1 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. The block diagram is shown in [Figure 1-1]. RF signals received

through the antenna are seperated by one Diplexer and one Duplexer..

RF Signal fed into the low noise amplifier (LNA) which is embedded in RFR6500 through the duplexer. Then,

they are 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)6800A

processes the data from ADC. The digital processing part is a demodulator.

In the case of transmission, RFT6150 receives OQPSK-modulated anlog signal from the MSM7500-1. The

RFT6150 connects directly with MSM7500-1 using an analog baseband interface. In RFT6150, the baseband

quadrature signals are upconverted to the Cellular bands and amplified to provide signal drive capability to the

power amp.

After that, the RF signal is amplified by the Power Amp 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 isolator and duplexer.

[Figure 1-1] RF Block Diagram Of KV800

Only for training and service purpose.

12

3.1.2 Description of Rx Part Circuit

3.1.2.1 Duplexer(DP1001)

The Duplexer consists of the Rx bandpass filter (BPF) and the Tx BPF which has the function of separating Tx

and Rx signals in the full duplex system for using the common antenna. The Tx part BPF is used to suppress

noises and spurious out of the Tx frequency band. The Rx BPF is used to receive only Rx signal coming from

the antenna, which is usually called preselector. It’s main function is to limit the bandwidth of spectrum

reaching the LNA and mixer, attenuate receiver spurious response and suppress local oscillator energy. As a

result frequency sensitivity and selectivity of mobile phone increase. The specification of LG-KV800 duplexer

is described below ;

● Cellular Duplexer

Pass Band Insertion Loss Return Loss Attenuation

48dB min (869~894MHz) 60dB min (824~849MHz) 60dB (824~849MHz)

Tx Rx Tx to Rx (min)

824~849MHz 869~894 MHz

2.0dB max 2.5dB max

12dB min 12dB min

50dB (869~894MHz)

3.1.2.3 LNAs (U1501)

The RFR6500 has cellular LNAs, respectively. 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 KV800 LNAs are described below.

● Cellular

High current mode Low current mode Passive status

Power Gain

*Gain mode G0(G2)

*Gain mode G1(G3)

Noise Figure

Gain mode G0(G2)

Gain mode G1(G3)

Input IP3

Gain mode G0(G2)

Only for training and service purpose.

16dB

4.0dB

1.4dB

4.0dB

8dB

13

14dB

3.0dB

1.4dB

4.0dB

-5dB

-6.0dB

-20.0dB

7.0dB

20.0dB

12dB

Gain mode G1(G3) 5dB -5dB 10dB

*Gain mode G0 and G1 operate in high and low current mode.

*Gain mode G2 and G3 operate in Passive status.

● GPS

Parameter GPS Band Unit

Gain 14.5 dB

Noise Figure 1.3 dB

IIP3 5.0 dBm

3.1.2.4 Down-converter Mixers

The RFR6500 device performs signal down-conversion for Cellular, PCS and GPS tri-band applications, but

LG-KV800 uses only Cellular and GPS. It contains all the circuitry (with the exception of external filters) needed

to support conversion of received RF signals to baseband signals. It consists of the three downconverting Mixers

(Cellular and GPS), and an RX VCO and RX PLL circuit.

The GPS LNA & mixers offer the most advanced and integrated CDMA Rx solution designed to meet

cascaded Noise Figure (NF) and Third-order Intercept Point (IIP3) requirements of IS-98C specifications for

Sensitivity, Two-Tone Intermodulation, and Single-tone Desense.

Operation modes and band selection are specially controlled from the Mobile Station Modem MSM7500-1.

The specification of LG-KV800 Mixers are described below:

● Cellular

High current mode Mid current mode Low current mode

Noise Figure

High Gain mode

Low Gain mode

Input IP3

High Gain mode

Low Gain mode

Input IP2

High Gain mode

10dB

25dB

4.0dB

-5.0dB

56dB

10dB

25dB

4.0dB

-5.0dB

56dB

9dB

25dB

-10.0dB

-5.0dB

40dB

Low Gain mode

30dB

Only for training and service purpose.

14

● Cellular

High current mode Mid current mode Low current mode

Noise Figure

High Gain mode

Low Gain mode

Input IP3

High Gain mode

Low Gain mode

Input IP2

High Gain mode

Low Gain mode

10dB

25dB

4.0dB

-11.0dB

56dB

30dB

10dB

25dB

-8.0dB

-11.0dB

56dB

30dB

9dB

25dB

-8.0dB

-11.0dB

40dB

30dB

3.1.2.4 Rx RF SAW FILTER(F1501)

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

frequency pick up, attenuate noise at the image frequency originating in or amplified by the LNA and suppress

second harmonic originating in the LNA. The Rx RF SAW filter usually called image filter.

3.1.3 Description of Transmit Part Circuit

3.1.3.1 RFT6150 (U1201)

The RFT6150 base-band-to-RF Transmit Processor performs all Tx signal-processing functions required

between digital base-band and the Power Amplifier Modulator (PAM). The base-band quadrature signals are

up-converted to the Cellular frequency bands and amplified to provide signal drive capability to the PAM.

The RFT6150 includes an RF mixer for upconverting analog baseband to RF, a programmable PLL for

generating Tx LO frequency, two cellular driver amplifiers and Tx power control through an 85dB VGA. As

added benefit, the single sideband upconversion eliminates the need for a band pass filter normally required

between the upconverter and driver amplifier.

I, I/, Q and Q/ signals proceed from the MSM7500-1 to RFT6150 are analog signal. In CDMA mode, These

signals are modulated by Quadrature Phase Shift King (QPSK). I and Q are 90 deg. out of phase, and I and I/ are

180 deg. The mixer in RFT6150 converts baseband signals into RF signals. After passing through the

upconverter , RF signal is inputted into the Power AMP.

Only for training and service purpose.

15

● RFT6150 Cellular CDMA RF Specifications

Condition Min. Typ. Max. Units

Rated Output Power

Min Output Power

Rx band noise power

ACPR

Average CDMA Cellular

CDMA Cellular

Cellular: Fc±885kHz

7 dBm

-75

-136 dBm/Hz

-56 dBc/

dBm

3.1.3.2 Power Amplifier(U1005)

The power amplifier that can be used in the CDMA mode has linear amplification capability and high efficiency.

For higher efficiency, it is made up of one MMIC (Monolithic Microwave Integrated Circuit) for which RF

input terminal and internal interface circuit are integrated onto one IC after going through the AlGaAs/GaAs

HBT (heterojunction bipolar transistor) process. The module of power amplifier is made up of an output end

interface circuit including this MMIC. The maximum power that can be inputted through the input terminal is

+10dBm and conversion gain is about 28dB. RF transmit signals that have been amplified through the power

amplifier are sent to the duplexer.

3.1.4 Description of Frequency Synthesizer Circuit

3.1.4.1 Voltage Control Temperature Compensation Crystal Oscillator (VCTCXO, U106)

The temperature variation of mobile phone can be compensated by VCTCXO. The reference frequency of a

mobile phone is 19.2MHz. The receives frequency tuning signals called TRK_LO_ADJ from MSM as

0.5V~2.5V DC via R and C filter in order to generate the reference frequency of 19.2MHz and input it into the

frequency synthesizer. Frequency stability depending on temperature is ±2.0 ppm.

Only for training and service purpose.

16

3.2. Digital/Voice Processing Part

3.2.1 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.

3.2.2 Configuration

3.2.2.1 Touch pannel and Receptacle Part

This is used to transmit Touch signals to MSM7500-1 via touch control IC .

and a receptacle that receives and sends out voice and data with external sources.

3.2.2.2 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 MSM7500-1, and

amplifying part that amplifies signals coming out from MIC and transferring them to the audio processor.

3.2.2.3 MSM (Mobile Station Modem) 7500-1 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.

3.2.2.4 Memory Part

The memory part is made up of a sdram/nand memory, nand for storing data.

3.2.2.5 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.

Only for training and service purpose.

17

3.2.3 Circuit Description

3.2.3.1 Touch pannel /LCD and Receptacle Part

Once the

processing.

The terminal status and operation are displayed on the screen for the user with the characters and icons.

Moreover, it exchanges audio signals and data with external sources through the receptacle, and then receives

power from the battery or external batteries.

Touch pannel

is pressed, the touch signals are sent out to MSM7500-1 via touch control IC for

3.2.3.2 Audio Processing Part

MIC signals are amplified through OP AMP, inputted into the audio codec(included in MSM6 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

MSM7500-1 activate the ringer by using signals generated in the timer in MSM7500-1.

3.2.3.3 MSM Part

The MSM7501A device integrates the ARM1136-J™ and ARM926EJ-S™ processor cores, offering the

ARM® Jazelle™ Java® hardware accelerator: one low-power, high-performance QDSP5000™ application

digital signal processor (aDSP) and one QDSP4000™ modem digital signal processor (mDSP) core, hardware

acceleration for

video, imaging, and graphics, and a wideband stereo codec to support enhanced digital audio applications. The

hardware acceleration eliminates the need for the multimedia companion processors normally required for video

and audio-based applications that support MP3 music files, a MIDI synthesizer, video and still image record and

playback,

and 2D/3D graphics functions. By removing the need for costly applications coprocessors and memory

subsystems, the MSM7501A solution reduces BOM costs and increases standby and talk times. QUALCOMM

provides a complete software suite and advance mobile subscriber software (AMSS) for building handsets based

on the MSM7501A chipset. AMSS software is designed to run on a SURF phone platform, an optional

development platform optimized to assist in evaluating, testing, and debugging AMSS software.

.

Only for training and service purpose.

18

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

3.2.3.4 Memory Part

MCP contents 1 Gbits flash memory and 1Gbit user memory and 1 Gbits SDRAM. 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 SDRAM data generated during the terminal operation are stored temporarily.

3.2.3.5 Power Supply Part

When the battery voltage (+4.0V) is fed and the PWR key of keypad is pressed, the power-up circuitry in PM

(power management) IC (U4300) is activated by the ON_SW signal, and then the LDO regulators embedded in

PMIC for MSM) are operated and +1.2V_MSMC1, +1.2V_MSMC2, +2.6V_MSMP3, +2.6V_MSMA and

+1.8V_MSME_P4 are generated.

The Rx part regulator (+2.85V_RX) is operated by the control signal of SLEEP/ from MSM7500-1

The Tx part regulator (+2.85V_TX) is operated by the I2C control signal from MSM7500-1

Only for training and service purpose.

19

3.2.3.6 Logic Part

The logic part consists of internal CPU of MSM, RAM, MCP. The MSM7500-1 receives TCXO (=19.2MHz)

from U1008 and controls the phone in CDMA mode. The major components are as follows:

z

CPU

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.

MCP

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.

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

z

Touch

Touch window is transmit Touch signals to MSM7500-1 via touch control IC (Sub PCB U1500)

Only for training and service purpose.

20

CHAPTER 4. Trouble shooting

4.1 Rx Part Trouble

4.1.1 When Rx Power isn’t enough

Test Point

RFR6500

RX SAW

Duplexer

TCXO

PMIC Part

Mobile s /w

Checking Flow

Rx TEST SETUP(HHP)

- Test Channel : 384

E5515C Setup

- CH : 384

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

START

1.Check

PMIC Circuit

2.Check

TCXO Circuit

Figure 1

4.Check LNA, RX SAW

5.Check

Control Signal

6.Check

Rx I/Q data

3.Check

Duplexer

Mobile SW

- 21 -

Redownload SW, CAL

4.1.2 Checking Regulator (PMIC) Circuit

Test Point

U4300 PMIC

Circuit Diagram

R4302 Up Pad

(PS_HOLD)

R4318 (+2.85V_RX)

Figure 2

Checking Flow

Check R4318

+2.85V_Rx OK?

Yes Yes

PMIC Circuit is OK

See next Page to check

TCXO

No

- 22 -

Check R4318 Up Pad

PS_HOLD High?

Replace U4300

No

Changing Board

4.1.3 Checking TCXO Circuit

Test Point Checking Flow

R1303

(TCXO)

R1301

(+2.85V_TCXO)

Circuit Diagram

TCXO

U1008

R1303

19.2MHz OK?

NO

R1301

2.85V OK? NO

Check U4300(PMIC)

Figure 3

YES

TCXO Circuit is OK

See next page to check

SBI control signal

Replace U1008

Waveform

Figure 4:

R1303 TCXO

- 23 -

Figure 5:

R1301 +2.85V_TCXO

4.1.4 Check Mobile S/W & Diplexer & Duplexer

Test Point

DP1001

Duplexer

U1001

M/S

C1508

(P1 : RFOUT to RX)

L1007

(P2 : RFIN From TX)

C1006

(P3 : RFOUT to M/S)

Checking Flow

Check C1006

Check C1508

Check L1007

Rx TEST SETUP(HHP)

- Test Channel : 384(DCN)

E5515C Setup

- CH : 384(DCN)

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

Level is Appear?

YES

Level is Appear?

YES

Level is Appear?

YES

Figure 6

NO

Replace U1001

NO

Replace DP1001

NO

Replace DP1001

Redownload SW and

Recalibration

- 24 -

4.1.4 Check Mobile S/W & Diplexer & Duplexer

Circuit Diagram

Waveform

C1508

Figure 7

- 25 -

4.1.5 Checking LNA & SAW (DCN,PCS)

Test Point

C1512

CELL_INP

C1511

CELL_INM

F1501

SAW Filter

Circuit Diagram

U1501

RFR6500

L1504

CLNA_OUT

Figure 8

- 26 -

4.1.5 Checking LNA & SAW (DCN,PCS)

Checking Flow

Rx TEST SETUP(HHP)

- Test Channel : 384(DCN)

E5515C Setup

- CH : 384(DCN)

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

waveform

Check LNA,

L1504 (RFR6500)

Check SAW, C1511,C1512)

Detected Signal? Changing U1501

Yes

Detected Signal?

Yes

See next Page to check

Rx I/Q data Signal

No

Changing F1501

Figure 9

- 27 -

LG KV800 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual