LG W3000 Service Manual

GSM Phone

SERVICE MANUAL

MODEL : W3000

P/N : XXXXX JUNE, 2002

SERVICE MANUAL MODEL : W3000

- 1 -

1. INTRODUCTION

.......................................

4

1.1 Purpose

..................................................

4

1.2 Regulatory Information

..........................

4

A. Security

..............................................

4

B. Incidence of Harm

..............................

4

C. Changes in Service

............................

4

D. Maintenance Limitations

....................

4

E. Notice of Radiated Emissions

.............

5

F. Pictures

..............................................

5

G. Interference and Attenuation

.............

5

H. Electrostatic Sensitive Devices

..........

5

1.3 Abbreviations

.........................................

6

2. PERFORMANCE

.....................................

8

2.1 H/W Feature

...........................................

8

2.2 Technical Specification

..........................

9

3. TECHNICAL BRIEF

............................

13

3.1 General Descreption

...........................

. 13

3.2 Receiver

...............................................

13

A. RF front end

.....................................

14

B. Demodulator and

baseband processing

......................

14

C. DC Offset Compensation

................

14

3.3 Transmitter Part

...................................

15

A. IF Modulator

...................................

. 15

B. OPLL

...............................................

16

C. Synthesizer

......................................

16

D. TX APC Part

....................................

17

E. Power Amplifier

................................

17

3.4 13 MHz Clock

......................................

18

3.5 Power Supplies and Control Signals

....

18

3.6 Digital Main Processor

.........................

19

3.7 Analog Main Processor

........................

24

3.8 Power Management

..............................

26

3.9 Memories

..............................................

28

3.10 Display and Interfaces

........................

28

3.11 Keypad Switches and Scanning

..........

29

3.12 Microphone

.........................................

30

3.13 Earpiece

.............................................

31

3.14 Hands-free Interface

..........................

32

3.15 Headset Jack Interface

.......................

32

3.16 Key Back-light Illumination

..................

32

3.17 LCD Back-light Illumination

................

33

3.18 Multi-Color LED Illumination

..............

33

3.19 Speaker & MIDI IC

.............................

34

4. TROUBLE SHOOTING

.....................

35

4.1 RF Components

.................................

35

4.2 Tx Trouble

..........................................

44

4.3 Power on Trouble

...............................

60

4.4 Charging Trouble

...............................

62

4.5 LCD Trouble

.......................................

64

4.6 Receiver Trouble .

...............................

66

4.7 Speaker Trouble

.................................

69

4.8 Mic Trouble

..........................................

72

4.9 Vibrator Trouble

.................................

75

4.10 Backlight Trouble

.............................

77

4.11 Folder on/off Trouble

........................

79

4.12 SIM Detect Trouble

..........................

81

4.13 Earphone Trouble

............................

83

4.14 HFK Trouble

.....................................

87

5. ASSEMBLY INSTRUCTION

............

95

5.1 Disassembly

.......................................

95

6. DOWNLOAD

.......................................

102

6.1 Download Setup

...............................

102

6.2 Download Procedure

........................

103

Table Of Contents

- 2 -

7. BLOCK DIAGRAM

.............................

106

7.1 Main Board

.......................................

106

7.2 FPCB

................................................

107

7.3 RF

....................................................

107

8. CIRCUIT DIAGRAM

...........................

109

8.1 Baseband Interface

..........................

109

8.2 MIDI

..................................................

110

8.3 KYE, I/F & LCD CON

.......................

111

8.4 RF

....................................................

112

9. PCB LAYOUT

.....................................

113

10. ENGINEERING MODE

..................

115

10.1 BB Test [MENU 1]

........................

115

10.2 RF Test [MENU 2]

........................

117

10.3 MF Mode [MENU 3]

......................

118

10.4 Trace option [MENU 4]

.................

119

10.5 Call Timer [MENU 5]

.....................

119

10.6 Fact. Reset [MENU 6]

...................

119

10.7 S/W version [MENU 7]

..................

119

11. STAND ALONE TEST

...................

120

11.1 Introduction

...................................

120

11.2 Setting Method

.............................

120

11.3 Means of Test

...............................

120

12. AUTO CALIBRATION

...................

121

12.1 Overview

.......................................

121

12.2 Requirements

...............................

121

12.3 Menu and settings

........................

121

12.4 AGC

..............................................

123

12.5 APC

..............................................

123

12.6 ADC

..............................................

123

12.7 Setting

..........................................

123

12.8 How to do calibration

....................

123

13. EXPLODED VIEW &
REPLACEMENT PART LIST

......

124

13.1 Exploded View

..............................

124

13.2 Accessories

..................................

126

13.3 Replacement Part List

..................

127

- 3 -

REVISED HISTORY

The information in this manual is subject to change without notice and should not be construed as
a commitment by LGE Inc. Furthermore, LGE Inc. reserves the right, without notice, to make
changes to equipment design as advances in engineering and manufacturing methods warrant.

This manual provides the information necessary to install, program, operate and maintain the LG-

W3000.

DATE ISSUE CONTENTS OF CHANGES S/W VERSION

JULY/2002 ISSUE 1 Initial Release

1. INTRODUCTION

- 4 -

1. INTRODUCTION

1.1 Purpose

This manual provides the information necessary to repair, calibration, description and download the
features of the LG-W3000.

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. LGE does
not warrant that this product is immune from the above case but will prevent unauthorized use of
common-carrier telecommunication service of facilities accessed through or connected to it. LGE
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 LG-W3000 or compatibility
with the network, 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 LG-W3000 must be performed only by the LGE or its authorized
agent. The user may not make any changes and/or repairs expect as specifically noted in this
manual. Therefore, note that unauthorized alternations or repair may affect the regulatory status of
the system and may void any remaining warranty.

1. INTRODUCTION

- 5 -

E. Notice of Radiated Emissions

The LG-W3000 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

An LG-W3000 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
systemboards.

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 -

1.3 Abbreviations

For the purposes of this manual, following abbreviations apply:0

APC Automatic Power Control

BB Baseband

BER Bit Error Ratio

CC-CV Constant Current – Constant Voltage

DAC Digital to Analog Converter

DCS Digital Communication System

dBm dB relative to 1 milliwatt

DSP Digital Signal Processing

EEPROM Electrical Erasable Programmable Read-Only Memory

EL Electroluminescence

ESD Electrostatic Discharge

FPCB Flexible Printed Circuit Board

GMSK Gaussian Minimum Shift Keying

GPIB General Purpose Interface Bus

GSM Global System for Mobile Communications

IPUI International Portable User Identity

IF Intermediate Frequency

LCD Liquid Crystal Display

LDO Low Drop Output

LED Light Emitting Diode

LG-W3000 LG GSM Phone

LGE LG Electronics

OPLL Offset Phase Locked Loop

PAM Power Amplifier Module

PCB Printed Circuit Board

PGA Programmable Gain Amplifier

PLL Phase Locked Loop

PSTN Public Switched Telephone Network

RF Radio Frequency

RLR Receiving Loudness Rating

RMS Root Mean Square

RTC Real Time Clock

SAW Surface Acoustic Wave

SIM Subscriber Identity Module

SLR Sending Loudness Rating

SRAM Static Random Access Memory

STMR Side Tone Masking Rating

TA Travel Adapter

1. INTRODUCTION

- 7 -

TDD Time Division Duplex

TDMA Time Division Multiple Access

UART Universal Asynchronous Receiver/Transmitter

VCO Voltage Controlled Oscillator

VCTCXO Voltage Control Temperature Compensated Crystal Oscillator

WAP Wireless Application Protocol

2. PERFORMANCE

- 8 -

2. PERFORMANCE

2.1 H/W Features

Item Feature Comment

Li-ion, 750 mAh

Standard Battery Size: 41 73.9 5mm

Weight: 22 g

AVG TCVR Current GSM , EGSM: 243 mA, DCS: 209 mA

Stand by Current < 4 mA

Talk time Up to 3 hours (GSM TX Level 7)

Stand by time Up to 200 hours (Paging Period: 9, RSSI: -85 dBm)

Charging time 2 hours 30mins

RX Sensitivity GSM, EGSM: -108 dBm, DCS: -107 dBm

TX output power GSM, EGSM: 32 dBm (Level 5)

DCS: 29.5 dBm (Level 0)

GPRS compatibility Class 10 (This only applies to G5200)

SIM card type 3V Small

Display 128 128 dots LCD(Main) , 96 64 dotsLCD(Sub)

Soft icons

Key Pad

Status Indicator 0 ~ 9, #, *, Navigation Key, Up/Down Side Key

Side Key, Confirm Key, Clear Key , Hot Key)

Send Key, END/PWR Key

ANT External

EAR Phone Jack Yes

PC Synchronization Yes

Speech coding EFR/FR/HR

Data and Fax Yes

Vibrator Yes

Receiver Yes

Roud Speaker Yes

Voice Recoding Yes

C-Mike Yes

Travel Adapter Yes

Options Hands-free kit, CLA, Data Kit

2. PERFORMANCE

- 9 -

2.2 Technical Specification

Item Description Specification

GSM

TX: 890 + n 0.2 MHz

RX: 935 + n 0.2 MHz (n = 1 ~ 124)

EGSM

1 Frequency Band TX: 890 + (n – 1024) 0.2 MHz

RX: 935 + (n – 1024) 0.2 MHz (n = 975 ~ 1024)

DCS

TX: 1710 + (n – 512) 0.2 MHz
Rx: 1805 + (n – 512) 0.2 MHz (n = 512 ~ 885)

2 Phase Error

RMS < 5 degrees
Peak < 20 degrees

3 Frequency Error < 0.1 ppm

GSM, EGSM

Level Power Toler. Level Power Toler.

5 33 dBm 2dB 13 17 dBm 3dB

6 31 dBm 3dB 14 15 dBm 3dB

7 29 dBm 3dB 15 13 dBm 3dB

8 27 dBm 3dB 16 11 dBm 5dB

9 25 dBm 3dB 17 9 dBm 5dB

10 23 dBm 3dB 18 7 dBm 5dB

11 21 dBm 3dB 19 5 dBm 5dB

4 Power Level 12 19 dBm 3dB

DCS

Level Power Toler. Level Power Toler.

0 30 dBm 2dB 8 14 dBm 3dB

1 28 dBm 3dB 9 12 dBm 4dB

2 26 dBm 3dB 10 10 dBm 4dB

3 24 dBm 3dB 11 8 dBm 4dB

4 22 dBm 3dB 12 6 dBm 4dB

5 20 dBm 3dB 13 4 dBm 4dB

6 18 dBm 3dB 14 2 dBm 5dB

7 16 dBm 3dB 15 0 dBm 5dB

2. PERFORMANCE

- 10 -

Item Description Specification

GSM, EGSM

Offset from Carrier (kHz). Max. dBc

100 +0.5

200 -30

250 -33

400 -60

600 ~ 1,200 -60

1,200 ~ 1,800 -60

1,800 ~ 3,000 -63

3,000 ~ 6,000 -65

5 Output RF Spectrum 6,000 -71

(due to modulation)

DCS

Offset from Carrier (kHz). Max. dBc

100 +0.5

200 -30

250 -33

400 -60

600 ~ 1,200 -60

1,200 ~ 1,800 -60

1,800 ~ 3,000 -65

3,000 ~ 6,000 -65

6,000 -73

GSM, EGSM

Offset from Carrier (kHz) Max. (dBm)

400 -19

600 -21

1,200 -21

6 Output RF Spectrum 1,800 -24

(due to switching transient)

GSM

Offset from Carrier (kHz) Max. (dBm)

400 -22

600 -24

1,200 -24

1,800 -27

7 Spurious Emissions Conduction, Emission Status

2. PERFORMANCE

- 11 -

Item Description Specification

GSM, EGSM

8 Bit Error Ratio

BER (Class II) < 2.439% @-102 dBm

DCS

BER (Class II) < 2.439% @-100 dBm

9 RX Level Report Accuracy 3 dB

10 SLR 8 3 dB

Frequency (Hz) Max.(dB) Min.(dB)

100 -12 -

200 0 -

300 0 -12

11 Sending Response 1,000 0 -6

2,000 4 -6

3,000 4 -6

3,400 4 -9

4,000 0 -

12 RLR 2 3 dB

Frequency (Hz) Max.(dB) Min.(dB)

100 -12 -

200 0 -

300 2 -7

500

*

-5

13 Receiving Response 1,000 0 -5

3,000 2 -5

3,400 2 -10

4,000 2

* Mean that Adopt a straight line in between 300 Hz

and 1,000 Hz to be Max. level in the range.

14 STMR 13 5 dB

15 Stability Margin > 6 dB

dB to ARL (dB) Level Ratio (dB)

-35 17.5

-30 22.5

16 Distortion

-20 30.7

-10 33.3

0 33.7

7 31.7

10 25.5

17 Side Tone Distortion Three stage distortion < 10%

18

System frequency (13 MHz) tolerance

≤ 2.5 ppm

2. PERFORMANCE

- 12 -

Item Description Specification

19 32.768KHz tolerance ≤ 30 ppm

Full power

< 243 mA (GSM, EGSM) ; < 209 mA (DCS)

20 Power Consumption

Standby

- Normal < 4 mA (Max. power)

21 Talk Time

GSM/ Level 7 (Battery Capacity 750mA): Up to 180

Min

GSM/ Level 12 (Battery Capacity 750mA): Up to 300 Min

Under conditions, Up to 200 hours:

1. Brand new and full 750mAh battery

2. Full charge, no receive/send and keep GSM in idle

22 Standby Time mode.

3. Broadcast set off.

4. Signal strength display set at 3 level above.

5. Backlight of phone set off.

At least 80 dB under below conditions:

23 Ringer Volume 1. Ringer set as ringer.

2. Test distance set as 50 cm

24 Charge Voltage

Fast Charge : < 500 mA

Slow Charge: < 60 mA

Antenna Bar Number Power

5 -85 dBm ~

4 -90 dBm ~ -86 dBm

25 Antenna Display 3 -95 dBm ~ -91 dBm

2 -100 dBm ~ -96 dBm

1 -105 dBm ~ -101 dBm

0~ -105 dBm

Battery Bar Number Voltage

0~ 3.62 V

26 Battery Indicator 1 3.62 ~ 3.73 V

2 3.73 ~ 3.82 V

3 3.82 V ~

27 Low Voltage Warning

3.5 0.03 V (Call)

3.62 0.03 V (Standby)

28 Forced shut down Voltage 3.35 0.03 V

1 Li-ion Battery

29 Battery Type

Standard Voltage = 3.7 V

Battery full charge voltage = 4.2 V

Capacity: 750 mAh

Switching-mode charger

30 Travel Charger Input: 100 ~ 240 V, 50/60 Hz

Output: 5.2 V, 600 mA

3. TECHNICAL BRIEF

- 13 -

3. TECHNICAL BRIEF

3.1 General Description

The RF parts consists of a transmitter part, a receiver part, a synthesizer part, a voltage supply part,
a VCTCXO part. And the main RF Chipset CX74017[U441]is a single-chip dual-band transceiver for
the extended global system for mobile communication[E-GSM900MHz]/Digital communication
system[DCS1800MHz] voice and data transfer applications.
This device integrated a direct conversion receiver architecture, which eliminates the need of
Intermediate Frequency, a transmitter based on a modulation loop architecture and fractional-N
synthesizer part with built in TXVCO and Local-VCO.

3.2 Receiver

The Receiver part in CX74017 contains all active circuits completely, full receiver chain with the
exception of discrete front-end RF SAW filters. The filtered and amplified signal is down converted
in the RF-mixer to the baseband output. The receiver path is supported by internal channel filtering.
The RF front-end circuit is shown Fig. 3-1.

Figure 3-1. RF front-end circuit.

ANT
S/W

CX74017

Base
Band

Block

DCS : 1805 ~ 1880MHz

GSM : 925 ~ 960MHz

90

0

90

0

2/3

RXIP
RXIN

RXQP

RXQN

4/3

PCS : 1805 ~ 1880MHz

f

vco

GSMSEL
DCSSEL

LMSP54AA-097

FAR-G6CS-1G8425-L257

3. TECHNICAL BRIEF

- 14 -

A. RF front end

RF front end consists of Antenna Switch(FL405), dual band LNAs integrated in transceiver(U441).
The Received RF signals (GSM 925MHz ~ 960MHz, DCS 1805MHz ~ 1880MHz) are fed into the
antenna or mobile switch. An antenna matching circuit is between the antenna and the mobile
switch.
The Antenna Switch (FL405) is used to control the Rx and TX paths. And, the input signals VC1
and VC2 of a FL405 are connected to DCSSEL(GPO_9) and GSMSEL(GPO_11) ports of U103 to
switch either TX or RX path on. When the RX path is turned on, the received RF signal then feeds
either Rx_900_RF or RX_1800_RF path controlled by GSM-RX and DCS-RX respectively. This
Rx_900_RF path contains one SAW filter, followed after the Antenna Switch (FL405), to filter any
unwanted signal apart from the DCS RX band. And, the RX_1800_RF path is the same case.

The logic and current for Antenna Switch is given below Table 3-1.

Table 3-1. The logic and current

These two paths are then connected to the LNAGSMN (#11) and LNADCSIN (#13) of CX74017
(U441), respectively. A low-noise bipolar RF amplifier, contained within the U441, amplifies the RF
signal. The RF signals from the front-end pass to the receiver mixers within the U441 device.

B. Demodulator and baseband processing

In direct conversion receiver there is only one mixer down-converting received RF signal to BB
signal directly. The gain down converting mixer is 40dB at high gain mode and 22dB at low gain
mode.
The Rx gain setting is done in the AGC algorithm. The nominal gain of the receiver is set as a
function of the expected signal strength at the antenna input so that a desired level is reached at
the Rx I/Q. 7 blocks in the receiver chain have variable gains, LNA, Mixer, LPF1, VGA1, gmC Filter,
Auxiliary gain control and VGA2. The gain settings can be adjustable via 3-wire bus control lines.
The baseband signals pass via integrated low-pass filters to the baseband A/D converters.
The remainder of the channel filtering is performed by the baseband chipset. The demodulator
contains switches to maintain the sense of the baseband I/Q outputs with respect to the incoming
RF signal on both GSM900 and DCS1800.

C. DC Offset Compensation

Three correction loops ensure that DC offsets, generated in the CX74017, do not overload the
baseband chain at any point.
After compensation, the correction voltages are held on capacitors for the duration of the receive
slot(s). A rising edge on the RXEN signal, selected via the serial interface, placed the DC
compensation circuitry in the track mode.

VC1 VC2 Current

GSM TX 0 V 2.7 V 10.0 mA max

DCS TX 2.7 V 0 V 10.0 mA max

GSM/DCS RX 0 V 0 V < 0.1 mA

3. TECHNICAL BRIEF

- 15 -

3.3 Transmitter Part

The Transmitter part contains CX74017 active parts, PAM and Antenna Switch. The CX74017
active part consists of a vector modulator and offset phase-locked loop block(OPLL) including
down-converter, phase detector, loop filter and dual band transmit VCO which can operate at either
final RF output frequency. The RF GMSK outputs from the transmit VCO are fed directly to the RF
power amplifiers.

Figure 3-2. Transmitter Block diagram

The peak output power and the profile of the transmitted burst are controlled by means of power
control loop. The power control function is integrated, eliminating the need for directional couplers,
detector diodes, power control IC and other power control circuitry. This allows the module to be
driven directly from the DAC output. The PA outputs from the directional coupler pass to the
antenna connector via Antenna Switch.

A. IF Modulator

The baseband converter(BBC) within the GSM chipset generates I and Q baseband signals for the
transmit vector modulator. The modulator provides more than 40dBc of carrier and unwanted side­band rejection and produces a GMSK modulated signal. The baseband software is able to cancel
out differential DC offsets in the I/Q baseband signals caused by imperfections in the D/A
converters.
The TX-Modulator implements a quadrature modulator. The IF-frequency input signal is split into
two precise orthogonal carriers, which are multiplied by the baseband modulation signal IT/ITX and
QT/QTX. It is used as reference signal for the OPLL.

ANT
S/W

GSM

TXVCO

PAM(RF3110)

CX74017

Base
Band

Block

DCS : 1710 ~ 1785MHz

GSM : 880 ~ 925MHz

90

0

LF

TXIP
TXIN

TXQP
TXQN

PFD

/D2

/D1

X2

DCS

f

vco

/3

X2

f

TX

f

IF

f

LO

GSMSEL

DCSSEL

TXPA

TXRAMP

BANDSEL1

LMSP54AA-097

B. OPLL

The offset mixer down converts the feedback Tx RF signal using LO to generate a IF modulating
signal. The IF signal goes via external passive bandpass filter to one port of the phase detector. The
other side of the phase detector input is LO signal. The phase detector generates an error current
proportional to the phase difference between the modulated signal from the offset mixer and the
reference signal from the LO.
The error current is filtered by a second order low-pass filter to generate an output voltage which
depends on the GMSK modulation and the desired channel frequency. This voltage controls the
transmit VCO such that the VCO output signal, centered on the correct RF channel, is frequency
modulated with the original GMSK data. The OPLL acts as a tracking narrowband band pass filter
tuned to the desired channel frequency. This reduces the wideband noise floor of the modulation
and up-conversion process and provides significant filtering of spurious products.

C. Synthesizer

The CX74017 includes a fully integrated UHF VCO with an on-chip LC tank.
A single sigma-delta fractional-N synthesizer can phase lock the local osillator used in both transmit
and receive path to a precision frequency reference input. Fractional-N operation offers low phase
noise and fast setting times, allowing for multiple slot applications such as GPRS.
The generated frequency is given by the following equation

where : = Generated VCO frequency

N = N-divider ratio integer part

FN = Fractional setting

R = R-divider ratio

= Reference Frequency

3. TECHNICAL BRIEF

- 16 -

=

VCOfVCO

f

3. TECHNICAL BRIEF

- 17 -

The counter and mode settings of the synthesizer are also programmed via 3-wire interface.

Figure 3-3. Synthesizer Block diagram

D. Power Amplifier

The RF3110[U416] is a Dual band amplifier for E-GSM(880 to 915MHz) and DCS1800(1710 to
1785MHz). The efficiency of module is the 50% at nominal output power for E-GSM and the 45%
for DCS1800. This module should be operated under the GSM burst pulse. To avoid permanent
degradation, CW operation should not be applied. To avoid the oscillation at no input power,
before the input is cut off, the control voltage Vapc should be control to less than 0.5V.
We have to improve thermal resistance, the through holes should be layouted as many as
possible on PCB under the module. And to get good stability, all the GND terminals should be
soldered to ground plane of PCB.

GSM

REFCLK

CX74017

Base
Band

Block

13MHz

Fractional-N

PLL

X2

DCS

/R

f

vco = (N+3.5+FN/2^22)fref/R

f

vco

f

ref

/3

LF

f

LO

AFC

13MHz

2V7_VTCXO

GSM

DCS

4/3 2/3

3.4 13 MHz Clock

The 13 MHz clock (VC-TCXO-208C) consists of a TCXO (Temperature Compensated Crystal
Oscillator) which oscillates at a frequency of 13 MHz.
It is used within the CX74017 RF Main Chip, BB Analog chip-set (AD6521), and Digital (AD6522).

Figure 3-4. VCTCXO Circuit.

3.5 Power Supplies and Control Signals

There are two regulators used in the phone to provide RF power. One is contained inside of
ADP3408 (U101), power management IC to provide the power for the VCTXO (X401). The other is
used to provide the power for remaining RF circuits.

Table 3-2.

Figure 3-5. Regulator Circuit.

3. TECHNICAL BRIEF

- 18 -

VC-TCXO-208C

1

5

4

3

CTL

GND OUT

VCC

23

SN74AHC1GU04DCKR

2V7_VTCXO

0R

15k

1n

1n

AFC

42

2.2u

(2012)

1M

1k

13MHz

FREF

ADP3330_2V85

OUT

IN

/ERR

/SD

NR

GND

1

2

3

6

5

4

10u

(2012)

0R

470p

RF2.85V

2.2u

VSYNTHEN

VBAT

Regulator Voltage Powers Enable Signal

Regulator 1
(U101, 2V7_VTCXO)

2.7 V

0.5 V VCTXO

Regulator 2
(U414, RF2V8)

2.85 V

0.5 V RF circuitry VSYNTHEN

3. TECHNICAL BRIEF

- 19 -

3.6 Testing Set-up and Checking Signals

A. Received RF Level and Checks

This section shows the typical RF levels expected throughout the receiver path. A block diagram
showing the locations of the RF measurement points and levels is shown in Fig. 3-11.

Receiver Testing Set-up

To check the receiver the following conditions have to be set:

On a signal generator or a GSM/DCS test box, output a CW signal of amplitude = -60 dBm at either:

947.4 MHz (CH62) when testing the GSM RX path or 1842. 6 MHz (CH699) when testing the DCS
RX path. Set the DC power supply to 4.0 V.

Note: All RF values shown are only intended as a guide figure and may differ from readings taken
with other test equipment and leads. Lead and connector losses should always be taken into
account when performing such RF measurements.

Testing Receiver

Using a suitable high frequency probe measure the RF levels at the relevant points shown in Fig. 3­9 and compare your measurements with those shown in the diagram. If there are any major
difference between the readings taken and those indicated then further investigation of that
particular point will be required. It will also be necessary to ensure that all the following power
supplies and signals are present which control this part of the receiver circuit :

1. The Control Signal of FEM (see Fig. 3-15, 16, 17)

2. RF2V8 (see Fig. 3-12)

3. 2V7_VTCXO (see Fig. 3-13)

4. 13MHz(see Fig. 3-14)

5. CLK, DATA, SEN (see Fig. 3-18)

8. RX IP, IN, QP, QN (see Fig. 3-21)

B. Transmitted RF Level and Checks

This section shows the typical RF levels expected throughout the transmitter path. A block diagram
showing the locations of the RF measurement points and levels is shown in Fig. 3-8.

Transmitter Testing Set-up

To check the transmitter the following conditions have to be set :

1. Set the DC Power supply to 4.0 V.

2. Power up the GSM/DCS test set and then establishing a call with an attached mobile on active
mode.

3. Select Channel, TX Level and Input Level according to which parameter is required.

Note: All RF values shown are only intended as a guide figure and may differ from readings taken
with other test equipment and leads. Lead and connector losses should always be taken into
account when performing such RF measurements.

3. TECHNICAL BRIEF

- 20 -

Testing Transmitter

Using a suitable high frequency probe measure the RF levels at the relevant points shown in Fig. 3­9, 10. and compare your measurements with those shown in the diagram. If there are any major
difference between the readings taken and those indicated then further investigation of that
particular point will be required. It will also be necessary to ensure that all the following power
supplies and signals are present which control this part of the transmitter circuit:

1. The Control Signal of FEM (see Fig. 3-15, 16, 17)

2. RF2V8 (see Fig. 3-12)

3. 2V7_VTCXO (see Fig. 3-13)

4. 13 MHz (see Fig. 3-14)

5. TXEN, TXRAMP, TXPA (see Fig. 3-19)

6. TX IP, IN, QP, QN (see Fig. 3-20)

3. TECHNICAL BRIEF

- 21 -

RF components (Component Side)

Figure 3-6. RF components (Component Side).

Reference Description Reference Description

U441 RF Main Chipset FL406 Dual SAW Filter

CN303 Mobile S/W X401 VCTCXO

FL405 Ant. S/W U414 LDO

U416 PAM U413 Inverter IC

CN303

FL405

U416

FL406

U441

U414

X401

U413

Test point of Rx Levels

Figure 3-7. Test point of Rx Levels.

3. TECHNICAL BRIEF

- 22 -

2

1

3

4

Test point of TX Levels

Figure 3-8. Test point of TX Levels(1).

3. TECHNICAL BRIEF

- 23 -

9 5

6

7

810

3. TECHNICAL BRIEF

- 24 -

Control signal test points (1)

Figure 3-9. Control signal test points (1).

VC2

U448

VC1

U444

RF

2.85V

TXQN TXIN

TXQP TXIP

TXQN TXIN
TXQP TXIP

13MHz
CLock

2V7_VCTCXO

TXRAMP(R401)

TXPA(R404)