LG G3100 Service Manual

Table Of Contents

1. INTRODUCTION................................…5

1.1 Purpose ............................................….

1.2 Regulatory Information ..........................

1.3 Abbreviations .........................................

5

5

7

2. PERFORMANCE ..............................….9

2.1 H/W Features .....................................…..

2.2 Technical Specification ..........................

10

3. TECHNICAL BRIEF ............................15

3.1 Transceiver ......…………………………..

3.2 Power Amplifier Module .....................….

3.3 13MHz Clock ……..………………………

3.4 Power Supplies for RF Circuits .........….

3.5 Testing Set-up and Checking Signals.….

3.6 Digital Main Processor ………………..….

3.7 Analog Main Processor ......................….

3.8 Power Management …….....................…

3.9 Memories ……………….....................….

3.10 Display and Interface ........................... .

3.11 Keypad Switches and Scanning ........ .

3.12 Microphone ........................................ .

3.13 Earpiece .....................………………..…

3.14 Hands free / Headset Interface ………..

3.15 Key Back-light Illumination ...............….

3.16 LCD Back-light Illumination ……………

3.17 Speaker & MIDI IC ..........................….

15

20

21

21

22

35

40

45

47

47

48

49

50

50

52

53

54

4. TROUBLE SHOOTING ................… 56

4.1 RF Components .............................….

4.2 Rx Trouble ..........................................

4.3 Tx Trouble ..........................................

4.4 Power On Trouble ..........................….

4.5 Charging Trouble ...........................….

4.6 LCD Trouble .......................................

9

4.7 Receiver Trouble ................................

4.8 Speaker Trouble .................................

4.9 Mic. Trouble ...................................….

4.10 Vibrator Trouble ...............................

4.11 Key Backlight LED Trouble ..............

4.12 SIM Detect Trouble ..........................

4.13 Earphone Trouble ............................

4.14 HFK Trouble ......................................

56

57

65

77

79

81

82

84

87

90

92

94

96

101

5. DISASSEMBLY INSTRUCTION .... 105

5.1 Disassembly .......................................

105

6. SOFTWARE DOWNLOAD ............. 108

6.1 Download Setup ............................…..

6.2 Download Procedure .......................…..

108

109

7. BLOCK DIAGRAM ........................... 114

-3 -

8. CIRCUIT DIAGRAM ......................... 115

8.1 Main Chipset and Memory ..............…..

8.2 Audio Part ………………….........……….

8.3 PMIC, LCD and I/O Connector …......….

8.4 RF Part ………..................................…..

115

116

117

118

9. PCB LAYOUT .................................. 119

13. EXPLODED VIEW &
REPLACEMENT PART LIST ...…. 137

13.1 Exploded View ...........................……

13.2 Accessory ...............................……..

13.3 Replacement Parts

< Mechanic component > ……………..

Replacement Parts

< Main component > ………………….

137

139

140

142

9.1 Rear Part …………………...............…..

9.2 Front Part ………………….........……….

119

120

10. ENGINEERING MODE .................. 121

10.1 BB Test [MENU 1] .....................……

10.2 RF Test [MENU 2] .....................……

10.3 MF Mode [MENU 3] ...................……

10.4 Trace option [MENU 4] ..............……

10.5 Call Timer [MENU 5] ..................……

10.6 Fact. Reset [MENU 6] ................……

10.7 S/W version [MENU 7] ...............……

121

123

123

124

124

124

124

11. STAND ALONE TEST ................... 125

11.1 What’s the Standalone Test? .....……

11.2 Standalone Test Equipment Setup…

11.3 H/W Test …….............................……

11.4 Tx Stand alone Test Setting …………..

11.5 Rx Stand alone Test Setting …………..

125

126

127

128

130

12. AUTO CALIBRATION ................... 132

12.1 Overview ....................................……

12.2 Equipment List ............................……

12.3 Equipment Setup ….........................…

12.4 AGC for RX ..…………………………..

12.5 APC for TX ……..………………………

12.7 How to do calibration .................……

132

132

133

134

134

135

-4 -

1. INTRODUCTION

1. INTRODUCTION

1.1 Purpose

This manual provides the information necessary to repair, calibration, description and download the
features of G3100.

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 may be risks of toll fraud associated
with your telecommunications system. System users are responsible for programming and configuring the
equipment to prevent unauthorized use. The manufacturer does not warrant that this product is immune
from the above case but will prevent unauthorized use of common-carrier telecommunication service of
facilities accessed through or connected to it. The manufacturer will not be responsible for any charges
that are resulted 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 this phone 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 this model must be performed only by the manufacturer or its authorized agent.
Therefore, note that unauthorized alternations or repair may affect the regulatory status of the system and
may void any remaining warranty.

-5 -

1. INTRODUCTION

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

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.

-6 -

1.3 Abbreviations

For the purposes of this manual, following abbreviations apply:

Automatic Power ControlAPC

BasebandBB

Bit Error RateBER

Constant Current – Constant VoltageCC-CV

Digital to Analog ConverterDAC

Digital Communication SystemDCS

1. INTRODUCTION

dB relative to 1 milli wattdBm

Digital Signal ProcessingDSP

Electrostatic DischargeESD

Flexible Printed Circuit BoardFPCB

Gaussian Minimum Shift KeyingGMSK

General Purpose Interface BusGPIB

Global System for Mobile CommunicationsGSM

International Portable User IdentityIPUI

Intermediate FrequencyIF

Liquid Crystal DisplayLCD

Low Drop OutputLDO

Light Emitting DiodeLED

Offset Phase Locked LoopOPLL

-7 -

1. INTRODUCTION

Power Amplifier ModulePAM

Printed Circuit BoardPCB

Programmable Gain AmplifierPGA

Phase Locked LoopPLL

Public Switched Telephone NetworkPSTN

Radio FrequencyRF

Receiving Loudness RatingRLR

Root Mean SquareRMS

Real Time ClockRTC

Surface Acoustic WaveSAW

Subscriber Identity ModuleSIM

Sending Loudness RatingSLR

Static Random Access MemorySRAM

Pseudo SRAMPSRAM

Side Tone Masking RatingSTMR

Travel AdapterTA

Time Division DuplexTDD

Time Division Multiple AccessTDMA

Universal Asynchronous Receiver/TransmitterUART

Voltage Controlled OscillatorVCO

Voltage Control Temperature Compensated Crystal OscillatorVCTCXO

Wireless Application ProtocolWAP

-8 -

2. PERFORMANCE

2.1 H/W Features

Item Feature Comment

Standard Battery

Stand by Current

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

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

Charging time 3hours

RX Sensitivity GSM, EGSM: -105dBm, DCS: -105dBm

2. PERFORMANCE

Li-ion, 850 mAh
Size: 42.08 × 66.65 × 9.3mm
Weight: 29.32g

Under the minimum current consumption environment
(such as paging period 9), the level of standby current
is below 4mA.

TX output power

GPRS compatibility Class 10

SIM card type 3V Small

Display 128 × 96 pixel 65K Color

Status Indicator

ANT Internal

EAR Phone Jack Yes

PC Synchronization Yes

Speech coding EFR/FR/HR

Data and Fax Yes

Vibrator Yes

Loud Speaker Yes

GSM, EGSM: 32dBm(Level 5),
DCS: 29dBm(Level 0)

Hard icons. Key Pad;
0 ~ 9, #, *, Up/Down Navigation Key
Confirm Key, Clear Key, Back Key,
Send Key, END/PWR Key

Voice Recoding Yes

C-Mike Yes

Receiver Yes

Travel Adapter Yes

Options Hands-free kit, CLA, Data Kit

-9 -

2. PERFORMANCE

2.2 Technical Specification

Item Description Specification

1 Frequency Band

GSM

TX: 890 + n × 0.2 MHz
RX: 935 + n × 0.2 MHz (n=1~124)

EGSM

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

3 Frequency Error < 0.1 ppm

4 Power Level

RMS < 5 degrees
Peak < 20 degrees

GSM, EGSM

Level Power Toler. Level Power Toler.

5 33dBm ±2dB 13 17dBm ± 3dB

6 31dBm ±3dB 14 15dBm ± 3dB

7 29dBm ±3dB 15 13dBm ± 3dB

8 27dBm ±3dB 16 11dBm ± 5dB

9 25dBm ±3dB 17 9dBm ± 5dB

10 23dBm ±3dB 18 7dBm ± 5dB

11 21dBm ±3dB 19 5dBm ± 5dB

12 19dBm ±3dB

DCS

Level Power Toler. Level Power Toler.

0 30dBm ±2dB 8 14dBm ± 3dB

1 28dBm ±3dB 9 12dBm ± 4dB

2 26dBm ±3dB 10 10dBm ± 4dB

3 24dBm ±3dB 11 8dBm ± 4dB

4 22dBm ±3dB 12 6dBm ± 4dB

5 20dBm ±3dB 13 4dBm ± 4dB

6 18dBm ±3dB 14 2dBm ± 5dB

7 16dBm ±3dB 15 0dBm ± 5dB

- 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

2. PERFORMANCE

3,000~ <6,000 -65

5

Output RF Spectrum
(due to modulation)

DCS

Offset from Carrier (kHz). Max. dBc

GSM, EGSM

6,000 -71

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

Offset from Carrier (kHz). Max. dBm

Output RF Spectrum

6

(due to switching

transient)

- 11 -

400 -19

600 -21

1,200 -21

1,800 -24

2. PERFORMANCE

Item Description Specification

GSM

Offset from Carrier (kHz). Max. dBm

Output RF Spectrum

6

7 Spurious Emissions Conduction, Radiation

8 Bit Error Rate

(due to switching

transient)

GSM, EGSM

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

DCS

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

400 -22

600 -24

1,200 -24

1,800 -27

9 RX Level Report Accuracy ±3 dB

10 SLR 8±3 dB

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

11 Sending Response

12 RLR 2±3 dB

100 -

200 -

300 -12

1,000 -6

2,000 -6

3,000 -6

3,400 -9

4,000 -

-12

0

0

0

4

4

4

0

- 12 -

Item Description Specification

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

2. PERFORMANCE

13 Receiving Response

* 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)

100 -

200 -

300 -7

500 -5

1,000 -5

3,000 -5

3,400 -10

4,000

-35

-30

-12

0

2

*

0

2

2

2

17.5

22.5

-20

16 Distortion

17 Side Tone Distortion Three stage distortion < 10%

18

19 32.768KHz tolerance ≤ 30 ppm

20 Ringer Volume

System frequency
(13 MHz) tolerance

≤ 2.5 ppm

At least 80 dB under below conditions:

1. Ringer set as ringer.

2. Test distance set as 50 cm

-10

0

7

10

30.7

33.3

33.7

31.7

25.5

- 13 -

2. PERFORMANCE

Item Description Specification

21 Charge Current

22 Antenna Display

23 Battery Indicator

24 Low Voltage Warning

CC Charge : < 500 mA

Trickle Charge : < 60 mA

Antenna Bar Number Power

5

4

3

2

1

0

Battery Bar Number Voltage

0

1

2

3

3.5 ± 0.03V (Standby)

3.62 ± 0.03V (Call)

-85 dBm ~

-90 dBm ~ -86 dBm

-95 dBm ~ -91 dBm

-100 dBm ~ -96 dBm

-105 dBm ~ -101 dBm

~ -105 dBm

~ 3.62 V

3.62 ~ 3.73 V

3.73 ~ 3.82 V

3.82 V ~

25

26 Battery Type

27 Travel Charger

Forced shut down
Voltage

3.35 ± 0.03V

1 Li-ion Battery
Standard Voltage = 3.7 V
Battery full charge voltage = 4.2 V
Capacity: 850mAh

Switching-mode charger
Input: 100 ~ 240 V, 50/60 Hz
Output: 5.2 V, 800 mA

- 14 -

3. TECHNICAL BRIEF

3. TECHNICAL BRIEF

3.1 Transceiver (CX74017, U401)

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[U401]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.

(1) Receiver Part

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.

LMSP54AA-097

DCS : 1805 ~ 1880MHz

GSM : 925 ~ 960MHz

ANT
S/W

GSMSEL
DCSSEL

PCS : 1805 ~ 1880MHz

FAR-G6CS-1G8425-L257

0

4/3

90

0

2/3

90

vco

f

Figure. 3-1 Receiver Block diagram

CX74017

RXQP
RXQN

RXIP
RXIN

Base
Band

Block

- 15 -

3. TECHNICAL BRIEF

A. RF Front End

RF front end consists of Antenna Switch(FL401), dual band LNAs integrated in transceiver(U401).
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 (FL401) is used to control the Rx and TX paths. And, the input signals VC1 and
VC2 of a FL401 are connected to DCSSEL(GPO_9) and GSMSEL(GPO_11) ports of U101 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 (FL401), 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

CurrentVC2VC1

10.0 mA max2.7 V0 VGSM TX

10.0 mA max0 V2.7 VDCS TX

<0.1 mA0 V0 VGSM/DCS RX

These two paths are then connected to the LNAGSMIN (#11) and LNADCSIN (#13) of
CX74017 (U401), respectively. A low-noise bipolar RF amplifier, contained within the U401,
amplifies the RF signal. The RF signals from the front-end pass to the receiver mixers
within the U401 device.

B. Demodulator and baseband processing

In direct conversion receiver there is only one mixer that is down-converting received RF signal to BB
signal directly. The gain of the 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.

- 16 -

3. TECHNICAL BRIEF

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.

- 17 -

3. TECHNICAL BRIEF

(2) Transmitter Part

The Transmitter part contains CX74017 active parts, power amplifier module (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.

GSMSEL

ANT

LMSP54AA-097

S/W

GSM : 880 ~ 925MHz

DCS : 1710 ~ 1785MHz

DCSSEL

PAM(RF3110)

TXRAMP
TXPA
BANDSEL1

vco

f

LO

f

X2

PFD

CX74017

IF

f

/D1

/D2

0

90

/3

X2

DCS

GSM

TX

f

LF

TXVCO

Base

Band

TXIP
TXIN

TXQP
TXQN

Block

Fig.3-2 Transmitter Block diagram

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.

- 18 -

3. TECHNICAL BRIEF

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.

(3) Synthesizer Part

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 oscillator 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.

FN



++

f



ref

22

2



R

f

=

VCO

where : = Generated VCO frequency

f

VCO

N = N-divider ratio integer part
FN = Fractional setting
R = R-divider ratio

f

VCO

= Reference Frequency



N



5.3



- 19 -

3. TECHNICAL BRIEF

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

4/3 2/3

DCS

/3

DCS

GSM

CX74017

2V7_VTCXO

GSM

f

vco

X2

f

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

LF

f

LO

Fractional-N

PLL

f

ref

/R

13MHz

Figure 3-3. Synthesizer Block diagram.

13MHz

AFC

REFCLK

Base
Band

Block

3.2 Power Amplifier Module

The RF3110[U402] is a dual band amplifier module for E-GSM(880 to 915MHz) and DCS1800(1710
to 1785MHz). The efficiency of the module is 50% at nominal output power for E-GSM and 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.
In order 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.

- 20 -

3. TECHNICAL BRIEF

3.3 13 MHz Clock

A VCTCXO (Voltage Controlled Temperature Compensated Crystal Oscillator, X401) is used as a
clock and oscillates at a frequency of 13MHz.
The output of the clock is fed to the CX74017 RF Main Chip, analog baseband chipset (AD6521,
U102), and digital baseband chipset (AD6522, U101)

Figure 3-4. VCTCXO Circuit.

3.4 Power Supplies for RF Circuits

Two regulators are used for RF circuits. One is ADP3330 (U404), the other is one port of ADP3408
(U301). ADP3330 (U404) supplies power to all the RF circuits except the VCTCXO(X401) that is
supplied power from ADP3408.

Enable SignalPowersVoltageRegulator

VCTCXO2.7V± 0.5VRegulator 1(U301,2V7_VTCXO)

VSYNTHENRF circuitry2.85V± 0.5VRegulator 2 (U404,RF2V8)

Figure 3-5. Regulator Circuit..

- 21 -

3. TECHNICAL BRIEF

3.5 Testing Set-up and Checking Signals

A. Received RF Power Level and Checks

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

Receiver Testing Set-up

To check the receiver the test equipment should be set as the following conditions:
On a signal generator or a GSM/DCS test box, output amplitude of CW sugnal = -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

Measure the RF power levels of the points which is shown in Fig. 3-9. If there are any major
difference between your measurement results and the values shown in the figure, then further
investigation about the particular point will be required. It will also be necessary to ensure that all the
following power supplies and signals which control this part of the receiver circuit are present :

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. PLL_CLK, PLL_DATA, PLL_LE (see Fig. 3-18)

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

B. Transmitted RF Power Level and Checks

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

Transmitter Testing Set-up

To check the transmitter the test equipment should be set as the following conditions:

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 be always taken into
account during the measurement.

- 22 -

3. TECHNICAL BRIEF

Testing Transmitter

Measure the RF power level of the points which are shown in Fig 3-9. If there are any major difference
between your measurement results and the values shown in the figure 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 which control this part of the transmitter circuit are present:

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)

- 23 -

3. TECHNICAL BRIEF

RF components (Component Side)

CN401

Mobile S/W

FL402

Dual Saw

Filter

U401

RF Main

Chipset

U404

LDO

X401

VCTCXO

FL401

Ant. S/W

U402

Power Amp

Module

U403

Inverter IC

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

Reference Description Reference Description

U401 RF Main Chipset FL402 Dual SAW Filter

CN401 Mobile S/W X401 VCTCXO

FL401 Ant. S/W U404 LDO

U402 PAM U403 Inverter IC

- 24 -

Test point of Rx Power Levels

3. TECHNICAL BRIEF

①

③

②

④

Figure 3-7. Test point of Rx Power Levels.

(Refer to Figure 3-9)

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3. TECHNICAL BRIEF

Test point of Rx Power Levels

⑤

⑥

⑨

⑩

⑦

⑧

Figure 3-8. Test point of Rx Power Levels.

(Refer to Figure 3-9)

- 26 -

RXIP

RXIN

CX74017

4/3

90

0

3

3. TECHNICAL BRIEF

Base

Band

Block

AFC

13MHz

2V7_VTCXO

RXQP

RXQN

2/3

90

0

4

-64 dBm

REFCLK

TXIP

PLL_LE

PLL_CLK

PLL_DATA

13MHz

I/O

Serial

ref

f

/R

ref/R

f

PLL

Fractional-N

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

f

LF

vco

f

TXEN

RXEN

FEENA

PLL_PD

I/O

Serial

/3

BANDSEL2

BANDSEL1

IF

f

LO

f

X2

X2

GSM

DCS

TX

f

TXIN

/D1

5

10 dBm

7

TXQP

TXQN

VBAT

VSYNTHEN

90

0

/D2

PFD

LF

TXVCO

/SD

OUT Vin

ADP3330_2V85

RF2.85V

TEMPSENSE

RF2.85V

6

8 dBm

Attanuator

Attanuator

TXEN

8

6 dBm

8 dBm

PAM(RF3110)

TXRAMP

-64.5 dBm

-61 dBm

-61 dBm

Dual Saw Filter L257

1

2

GSM

925 ~ 960MHz

GSMSEL

TXPA

DCSSEL

ANT

LMSP54AA-097

S/W

DCS

1805~1880MHz

-60 dBm

Figure 3-9. Transmitter & Receiver RF Levels

- 27 -

9

34 dBm32 dBm

10

GSM : 880~925MHz

DCS : 1710 ~ 1785MHz

3. TECHNICAL BRIEF

Control signal test points (1)

VC2

VC1

RF2.85V

TX_RAMP

13MHz

Clock

VCTCXO2.7V

TXIQ

TX_PA

RXIQ

PLL_LE

Figure 3-10. Control signal test points (1).

(Refer to Figure 3-12~21)

- 28 -

Control signal test points (2)

3. TECHNICAL BRIEF

PLL_CLK

PLL_DATA

TX_EN

RX_EN

Figure 3-11. Control signal test points (2).

(Refer to Figure 3-18)

- 29 -

3. TECHNICAL BRIEF

2.85V

2.85V

Figure 3-12. Regulator Output (RF2V85)

Figure 3-13. VCTCXO Power Supply (2V7_VTCXO).

- 30 -

3. TECHNICAL BRIEF

Figure 3-14. 13MHz Clock.

VC1=0V

VC2=0V

Figure 3-15. Control Signal (VC1,VC2) in Rx mode (GSM, DCS both).

- 31 -

3. TECHNICAL BRIEF

VC1

VC2

VC1

VC2

Figure 3-16. Control Signal (VC1,VC2) in DCS TX mode.

Figure 3-17. Control Signal (VC1,VC2) in GSM TX mode.

- 32 -