LG KG920 Service Manual

Date: April, 2006 / Issue 1.0

kg920 cover 2006.5.15 10:6 AM ˘`1

Service Manual

Service Manual

Model : KG920

KG920

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

1.1 Purpose ..................................................... 5

1.2 Regulatory Information ............................... 5

1.3 Abbreviations .............................................. 7

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

2.1 H/W Features...............................................9

2.2 Technical Specification ..............................18

3. TECHNICAL BRIEF............................23

3.1 Transceiver (SI4210) .................................23

3.2 PAM (SKY77328) ..................................... 27

3.3 26 26 MHz Clock (VCTCXO) .....................28

3.4 Power Supplies for RF Circuits (RF LDO) .28

3.5 Digital Main Processor (AD6527B) ............30

3.6 Analog Main & Power Management

Processor (AD6535) ..................................36

3.7 Battery Charging Block ..............................43

3.8 MUMTI-MEDIA INTERFACE .....................47

3.9 MIDI IC(YMU787) ......................................59

3.10 MEMORY

(512Mbits NOR + 128Mbits PSRAM) ......63

3.11 Keypad Switches and Scanning ..............66

3.12 Main Microphone .....................................68

3.13 Main Receiver..........................................69

3.14 Headset Interface ....................................70

3.15 BLUETOOTH(LBMA-2C67B2) ................71

3.16 Mini-SD ....................................................72

3.17 FLIP SWITCH ..........................................73

3.18 VIBRATOR ..............................................74

3.19 Audio CODEC..........................................74

3.20 KEY backlight ..........................................75

4. TROUBLE SHOOTING.......................76

4.1 RF Component ..........................................76

4.2 BT Trouble .................................................86

4.3 Power On Trouble......................................89

4.4 Charging Trouble .......................................91

4.5 Vibrator Trouble .........................................93

4.6 SIM Card Trouble ......................................95

4.7 KEY backlight Trouble ...............................97

4.8 Side KEY backlight Trouble (SUB board) ..99

4.9 RTC Trouble ............................................101

4.10 Swivel Trouble .......................................103

4.11 LCD Trouble ..........................................105

4.12 Camera Trouble.....................................108

4.13 Speaker Trouble ....................................120

4.14 Headphone Trouble ...............................122

4.15 Receiver Trouble ...................................124

4.16 Microphone Trouble...............................126

5. DOWNLOAD AND CALIBRATION...128

5.1 Download.................................................128

5.2 Calibration................................................134

6. BLOCK DIAGRAM ...........................140

7. Circuit Diagram................................141

8. pcb layout ........................................149

9. ENGINEERING MODE .....................157

9.1 About Engineering Mode .........................157

9.2 Access Codes..........................................157

9.3 Key Operation..........................................157

9.4 Engineering Mode Menu Tree .................157

9.5 BB Test [MENU 1] ...................................158

9.6 RF Test [MENU 2] ...................................160

9.7 MF mode [MENU 3] .................................160

9.8 Trace option [MENU 4] ............................161

9.9 Call timer [MENU 5] .................................161

9.10 Fact. Reset [MENU 6]............................162

9.11 S/W version [MENU 7]...........................162

9.12 MM S/W Download [MENU 8] ...............162

12. EXPLODED VIEW & REPLACEMENT

PART LIST ..................................... 163

12.1 Exploded View ...................................... 163

12.2 Replacement Parts ................................165

12.3 Accessory ............................................. 194

Table Of Contents

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1. INTRODUCTION

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1.1 Purpose

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

1.2 Regulatory Information

A. Security

Toll fraud, the unauthorized use of telecommunications system by an unauthorized part (for example,
persons other than your company”s employees, agents, subcontractors, or person working on your
company”s behalf) can result in substantial additional charges for your telecommunications services.
System users are responsible for the security of own system. There are may be risks of toll fraud
associated with your telecommunications system. System users are responsible for programming and
configuring the equipment to prevent unauthorized use. The manufacturer does not warrant that this
product is immune from the above case but will prevent unauthorized use of common-carrier
telecommunication service of facilities accessed through or connected to it.
The manufacturer will not be responsible for any charges that result from such unauthorized use.

B. Incidence of Harm

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

C. Changes in Service

A local telephone company may make changes in its communications facilities or procedure. If these
changes could reasonably be expected to affect the use of the 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. 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 any
remaining warranty.

1. INTRODUCTION

1. INTRODUCTION

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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.

1. INTRODUCTION

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1.3 Abbreviations

For the purposes of this manual, following abbreviations apply:

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 milli watt

DSP Digital Signal Processing

EEPROM Electrical Erasable Programmable Read-Only Memory

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

OPLL Offset Phase Locked Loop

1. INTRODUCTION

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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

PSRAM Pseudo SRAM

STMR Side Tone Masking Rating

TA Travel Adapter

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

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2.1 H/W Features

1) System Specification

Item Target Specification

Form Factor Twisted Bar

Size 108 x 50 x 18mm

Weight 150g

Battery 3.7V, 820 mAh LI-Ion

Talk Time Up to 3h : GSM Tx Level 7

Standby Time Up to 180 hrs : Paging Period 9, RSSI 85dBm

Antenna Internal Antenna

LCD Main: 262K Colour QVGA(240x320) TFT

Camera Built-in CCD 5M Pixels Camera

Back Light(Key Pad) LED

Back Light colour(Key) Blue(with orange colour filter)

Vibrator Yes

Buzzer Yes

C-MIC Yes

Receiver Yes

Earphone Jack Yes / Jack

SIM Socket Yes (SIM Block Type) → 3V only

Volume Key Yes

Voice Key N/A

I/O Connect 24 Pin

Basic Accessory Travel Adaptor / Battery / Ear Phone + Mic/Data Cable/Mini-SD Card

Option N/A

2. PERFORMANCE

2) Feature

2. PERFORMANCE

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Function Target Specification

RSSI (5 Level)

Battery Charging (5 Level)

Display

RTC

Multi-Language (English, French, German, Spanish, Dutch, etc.)

Quick Access Mode(HOT KEY)

PLMN/Service Indicator

Number of Keys : 30 Key (including Soft key, side key, Hot key)

Keypad

Soft Function Keys : 3

International Access (+)(long 0)

HotKey : Zoom+/-, MP3, Schedule

Normal Features Last Dialled Number : 20

Last Received Number : 10

Last Missed Number : 10

Scratch Pad Memory(Save a phone number in call) : 1

Call Waiting

Call Swap

Call Retrieve

Any Key Answer

Automatic Redial

Calling Line Identification

Call Management Full Call divert

Speed Dialling

Last Number Redial

Multi-party Call (Conference Call)

Voice Recording Voice Recording (20 Sec/20 message)

Automatic Network Selection

Network Manual Network Selection

Network Service Status

2. PERFORMANCE

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Read Cell Broadcast

Cell Broadcast Cell Broadcast Categories

Cell Broadcast Message Language

Number Store and Recall

Alpha Store and Recall

Search the Phone Book in call

Scroll by alpha

Last Number Dialled (20)

Phone Book

Last Number Missed (10)

Last Number Received (10)

Copy & Move

Fixed Dial Number

Service Dial Number

Email Entry

Entry : 1000 names

Last Call Timer

Last Call Charge Units

Call Cost Total Call Timer

Total Charge Units

Visible, Audible Call Time/Cost Indication

Key tone setting

Key / Ring Tone Volume (5 Level)

Ring Tone Pattern 20(fixed) + My Folder Ring tone 24(Default)

Audio Ring Type:

Silent / Vibrator & Ring / Ring only / Vibrator only/Ring after Vibrator

Earpiece Volume (5 Level)

Mute

DTMF

DTMF Signalling

DTMF Enable & Disable

2. PERFORMANCE

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Call Forwarding All Incoming Calls

Call Forwarding On Busy

Call Forwarding No Reply

Call forwarding Not-reachable

Supplementary Services

Call Barring All Outgoing Calls

Call Barring All Outgoing International Calls

Call Barring All incoming Calls

Call Barring All incoming Calls when roaming

Conference Call (up to 5 calls)

Plug-In Type : 3V Only

SIM

Service Provider Lock & Network Lock

SIM Toolkit (Class 1, 2, 3)

Prepaid SIM Operation

Read Message

Write and Edit Message

Send and Receive Message

Reply to Message

Forward Message

Extract Number from Message

Message Status

Short Message Message Unread Indicator

Settable Message Center Number,

Visible and Audible Message

Voice Mail

Settable Voice Mail Center Number

Message Protocol

Message Overflow Indicator

Message Center Number

Multi-Band Support of Multi-band & Mode

Development & Test Facility

Miscellaneous Function

Field Test Facility

Display Software Version

IMEI

2. PERFORMANCE

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Text Input T9 (Predictive word input)

Organizer Calendar & Memo

World Time

Setting Local time

Number of Selectable Cities: 76

Unit converter Currency/Surface/Length/Weight/Temperature/Volume/Velocity/Shoes

/Clothes

Calculator Addition, Subtraction, Multiplication, Division, trigonometrical function ,

logarithmic function

Scheduler , Memo Sync

Phone Book Sync

PC Sync Internet Kit supporting PC OS (2000,ME,XP)

Contents D/Load (Wallpaper/Ringtone)

Data Circuit (up to 9.6kbps)

GPRS GPRS Multi slot Class 10

Game Java Download Games

Menu Quick Access Mode

Read Software Version

Handset Battery Charging Mode

Restore Factory Setting

Security

SIM Lock

Emergency Call

12/24 hour

Calendar with Automatic Leap Year Adjustment

Time Zone Adjustment

Real Time Clock

Alarm Manager

On Alarm Event

Display Message on Alarm Event

Others Profiles

2. PERFORMANCE

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Read and Save MMS Message

Preview MMS Message

Send and Receive MMS Message

Previous, Next slide

MMS (3GPP R5)

Set timer

Remove media

Delete slide

Attach MMS media (Text, Audio, Picture)

Audio: SP-MIDI, I-Melody (AMR: supported), MIDI, SMAF, WAV

Picture: GIF87,GIF89a, PNG, JPEG, WBMP

WAP version 2.0 @ TELECA

JAVA MIDP 2.0 @ Esmertec

E-mail (CIS/Europe) SMTP, POP3

Bluetooth Generic Access Profile,

Service Discovery application Profiles(profile v1.1),

Generic Objective Exchange Profile,

Serial Port Profile, Headset Profile (profile v1.1),

Audio Gateway,

Dial-Up Networking profile (profile v1.1),

File Transfer Profile (Server, Client) (profile v1.1),

Object Push Profile (Server, Client) (profile v1.1, Vcard2.1 only),

Hands-Free profile (profile v1.0),

Basic Printing Profile (profile v1.0)

2. PERFORMANCE

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3) RF Transmitter

NO Item EGSM DCS1800

100kHz ~ 1GHz -36dBm -36dBm

1GHz ~ 12.75GHz -30dBm

1GHz ~ 1710MHz -30dBm

1710MHz ~ 1785MHz -36dBm

1785MHz ~ 12.75GHz -30dBm

100kHz ~ 880MHz -57dBm -57dBm

880MHz ~ 915MHz -59dBm -59dBm

915MHz ~ 1GHz -57dBm -57dBm

1GHz ~ 1.710GHz -47dBm -47dBm

1.710GHz ~ 1.785GHz -53dBm -53dBm

1.785G ~ 12.75GHz -47dBm -47dBm

1GHz ~ 1.850GHz

1.850GHz ~ 1.910GHz

1.910GHz ~ 12.75GHz

30M ~ 1GHz -36dBm -36dBm

1G ~ 4GHz -30dBm

1G ~ 1710MHz -30dBm

1710M ~ 1785MHz -36dBm

1785M ~ 4GHz -30dBm

30M ~ 880MHz -57dBm

880M ~ 915MHz -59dBm

915M ~ 1GHz -57dBm

1G ~ 1710MHz -47dBm

1710M ~ 1785MHz -53dBm

1785M ~ 4GHz -47dBm

1G ~ 1850MHz

1850M ~ 1910MHz

1910M ~ 4GHz

Conducted

Spurious

Emission

MS allocated

Channel

Idle Mode

MS allocated

Channel

Idle Mode

Radiated

Spurious

Emission

Frequency Error

Phase Error

< 0.1ppm

Peak < 20 degrees RMS < 5 degrees

1

2

3

2. PERFORMANCE

- 16 -

NO Item EGSM DCS1800

Frequency Error Under 3dB below reference sensitivity 3dB below reference sensitivity

Multipath and Interference RA250: ±300Hz RA130: ±400Hz

Condition HT100: ±180Hz HT100: ±350Hz

TU50: ±160Hz TU50: ±260Hz

TU3: ±230Hz TU1.5: ±320Hz
0 ~ 100kHz +0.5dB 0 ~ 100kHz +0.5dB
200kHz -30dB 200kHz -30dB
250kHz -33dB 250kHz -33dB
400kHz -60dB 400kHz -60dB
600 ~ 1800kHz -60dB 600 ~ 1800kHz -60dB
1800 ~ 3000kHz -63dB 1800 ~ 6000kHz -65dB
3000 ~ 6000kHz -65dB ≥ 6000kHz -73dB
≥ 6000kHz -71dB
400kHz -19dB 400kHz -22dB
600kHz -21dB 600kHz -24dB
1200kHz -21dB 1200kHz -24dB
1800kHz -24dB 1800kHz -27dB

Frequency offset 800kHz

Intermodulation product should
be Les s than 55dB below the
level of Wanted signal

Power control Power Tolerance Power control Power Tolerance

Level (dBm) (dB) Level (dBm) (dB)

533+3030+3
631+3128+3
729+3226+3
827+3324+3
925+3422+3

10 23

+

3520+3

11 21

+

3618+3

12 19

+

3716+3

13 17

+

3814+3

14 15

+

3912+4

15 13

+

31010+4

16 11

+

5118+4

17 9

+

5126+4

18 7

+

5134+4

19 5

+

5142+5

15 0

+

5

Output RF

Spectrum

Due to

modulation

Due to Switching

transient

Intermodulation attenuation

Transmitter Output Power

4

5

6

7

2. PERFORMANCE

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2) Receiver

NO Item GSM900 DCS1800

Sensitivity (TCH/FS Class II) -105dBm -105dBm

Co-Channel Rejection

(TCH/FS Class II, RBER, TUhigh/FH)

C/Ic= 7dB C/Ic= 7dB

Adjacent Channel Rejection

200kHz C/Ia1= -12dB C/Ia1= -12dB

400kHz C/Ia2= -44dB C/Ia2= -44dB

Wanted Signal: -98dBm Wanted Signal: -96dBm

Intermodulation Rejection 1’st interferer: -44dBm 1’st interferer: -44dBm

2’nd interferer: -45dBm 2’nd interferer: -44dBm

Blocking Response

Wanted Signal: -101dBm Wanted Signal: -101dBm

(TCH/FS Class II, RBER)

Unwanted Signal: Depend Unwanted Signal: Depend

on freq. on freq.

1

2

3

4

5

2. PERFORMANCE

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2.2 Technical Specification

Item Description Specification

EGSM

TX: 890 + (n-1024) x 0.2 MHz
RX: 935 + (n-1024) x 0.2 MHz (n=975~1024)

DCS

1Frequency Band TX: 1710 + (n-512) x 0.2 MHz

RX: 1805 + (n-512) x 0.2 MHz (n=512~885)

PCS

TX: 1810 + (n-512) x 0.2 MHz
RX: 1905 + (n-512) x 0.2 MHz (n=512~885)

2 Phase Error

RMS < 5 degrees
Peak < 20 degrees

3 Frequency Error < 0.1 ppm

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, PCS

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

- 19 -

Item Description Specification

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, PCS

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

EGSM

Offset from Carrier (kHz) Max. (dBm)

Output RF Spectrum 400 -19

6

(due to switching transient) 600 -21

1,200 -21

1,800 -24

2. PERFORMANCE

- 20 -

Item Description Specification

DCS, PCS

Offset from Carrier (kHz). Max. (dBm)

Output RF Spectrum 400 -22

6

(due to switching transient) 600 -24

1,200 -24

1,800 -27

7 Spurious Emissions Conduction, Emission Status

EGSM

8 Bit Error Ratio

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

DCS, PCS

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.

2. PERFORMANCE

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Item Description Specification

14 STMR 13 5 dB

15 Stability Margin > 6 dB

dB to ARL (dB) Level Ratio (dB)

-35 17.5

-30 22.5

-20 30.7

16 Distortion

-10 33.3

0 33.7

7 31.7

10 25.5

17 Side Tone Distortion Three stage distortion < 10%

18

System frequency

2.5ppm

(26 MHz) tolerance

19 32.768KHz tolerance 30ppm

At least 58 dBspl under below conditions:

20 Ringer Volume 1. Ringer set as ringer.

2. Test distance set as 1 m

21 Charge Current

Fast Charge : Typ. 700 mA
Slow Charge : Typ. 70 mA

Antenna Bar Number Power

5 -85 2 dBm

5 → 4 -85 2 dBm

22 Antenna Display 4 → 3 -90 2 dBm

3 → 2 -95 2 dBm

2 → 1 -100 2 dBm

1 → 0 -105 2 dBm

Battery Bar Number Voltage

0 3.36 ~ 3.54 V

23 Battery Indicator 1 3.55 ~ 3.66 V

2 3.67 ~ 3.72 V

3 3.73 ~ 3.84 V

4 3.85 V ~

24 Low Voltage Warning

3.55 0.03V (Call)

3.48 0.03V (Standby)

2. PERFORMANCE

- 22 -

Item Description Specification

25 Forced shut down Voltage 3.35 0.03 V

2 Li-Ion Battery

26 Battery Type

Standard Voltage = 3.7 V
Battery full charge voltage = 4.2 V
Capacity: 820mAh

Switching-mode charger

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

Output: 5.2 V, 800 mA

3. TECHNICAL BRIEF

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3.1 Transceiver (SI4210)

The RF parts consist of a transmitter part, a receiver part, a frequency synthesizer part, a voltage
supply part, and a VCTCXO part.
The Aero I transceiver is the integrated RF front end for multi-band GSM/GPRS digital Cellular
handsets and wireless data modems. The integrated solution eliminates the IF SAW filter, external low
noise amplifier (LNAs) for three bands, transmit and RF voltage controlled oscillator VCO modules,
and other discrete components found in conventional designs.

3. TECHNICAL BRIEF

Figure. 3-1 RECEIVER FUNCTIONAL BLOCK DIAGRAM

3. TECHNICAL BRIEF

- 24 -

(1) Receiver Part

The Aero I transceiver uses a low-IF receiver architecture which allows for the on chip integration of the
channel selection filters, eliminating the external RF image reject filters and the IF SAW filter required in
conventional super-heterodyne architectures.

A. RF front end

RF front end consists of Front End Module(FL501) and dual band LNAs integrated in transceiver (U502).
The Received RF signals(GSM 925MHz ~ 960MHz, DCS 1805MHz ~ 1880MHz PCS 1905MHz ~
1980MHz) are fed into the antenna or Mobile switch.
The Front End Module(FL501) is used to control the Rx and Tx paths. And, the input signals VC1, VC2,
VC3 of a FL500 are directly connected to baseband controller to switch either Tx or Rx path on.
The logic and current is given below Table 3-1

Three differential-input LNAs are integrated in SI4210. The GSM input supports the GSM 850 (864­894MHz) or E-GSM 900 (925-960MHz) bands. The DCS input supports the DCS 1800 (1805-1880 MHz)
band. The PCS input supports the PCS 1900 (1930-1990 MHz) band.
The LNA inputs are matched to the 150 Ω balanced output SAW filters through external LC matching
networks. The LNA gain is controlled with the LNAG[1:0] and LNAC[1:0] bits in register 05h (Figure 3-2).

VC1 VC2 VC3

GSM Tx 0V 0V 2.5 ~ 3.0 V

DCS, PCS Tx 0V 2.5 ~ 3.0 V 0 V

GSM / DCS Rx 0V 0 V 0 V

GSM / DCS Rx 2.5 ~ 3.0 V 0 V 0 V

Table 3-1 THE LOGIC AND CURRENT

3. TECHNICAL BRIEF

- 25 -

B. Intermediate frequency (IF) and Demodulation

A quadrature image-reject mixer downconverts the RF signal to a 100KHz intermediate frequency (IF) with
the RFLO from the frequency synthesizer. The RFLO frequency is between 1737.8 to 1989.9 MHz, and is
internally divided by 2 for GSM 850 and E-GSM 900 modes. The mixer output is amplified with an analog
programmable gain amplifier (PGA), which is controlled with the AGAIN[2:0] bits in register 05h (Figure3-2).

The quadrature IF signal is digitized with high resolution A/D converters (ADCs).
The ADC output is downconverted to baseband with a digital 100KHz quadrature LO signal. Digital
decimation and IIR filters perform channel selection to remove blocking and reference interference signals.
The selectivity setting (CSEL=0) or a low selectivity setting (CSEL=1). The low selectivity filter has a flatter
group channelization filter is in the baseband chip. After channel selection, the digital output is scaled with a
digital PGA, which is controlled with the DGAIN [5:0] bits in register 05h.

The amplified digital output signal go through with DACs that drive a differential analog signal onto the
RXIP,RXIN,RXQP and RXQN pins to interface to standard analog ADC input baseband ICs. No special
processing is required in the baseband for offset compensation or extended dynamic range.
Compared to a direct-conversion architecture, the low-IF architecture has a much greater degree of
immunity to dc offsets that can arise from RF local oscillator(RFLO) self-mixing, 2nd order distortion of
blockers, and device 1/f noise.

Figure. 3-2 SI4210 RECEIVER PART

3. TECHNICAL BRIEF

- 26 -

(2) Transmitter Part

The transmit (Tx) section consists of an I/Q baseband upconverter, and offset phase-locked loop (OPLL)
and two output buffers that can drive external power amplifiers (PA), one for the GSM 850 (824-849 MHz)
and E-GSM 900 (880-915 MHz) bands and one for the DCS 1800 (1710-1785 MHz) and PCS 1900 (1850­1910MHz) bands.

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. A quadrature mixer upconverts the differential in­phase (TXIP, TXIN) and quadrature (TXQP, TXQN) signals with the IFLO to generate a SSB IF signal that
is filtered and used as the reference input to the OPLL.
The IFLO frequency is generated between 766 and 896 MHz and internally divided by 2 to generate the
quadrature LO signals for the quadrature modulator, resulting in an IF between 383 and 448 MHz. For the
E-GSM 900 band, two different IFLO frequencies are required for spur management. Therefore, the IF PLL
must be programmed per channel in the E-GSM 900 band.

Figure. 3-3 SI4210TRANSMITTER PART

3. TECHNICAL BRIEF

- 27 -

B. OPLL

The OPLL consists of a feedback mixer, a phase detector, a loop filter, and a fully integrated TXVCO. The
TXVCO is centered between the DCS 1800 and PCS 1900 bands, and its output is divided by 2 for the
GSM 850 and E-GSM 900 bands. The RFLO frequency is generated between 1272 and 1483 MHz. To
allow a single VCO to be used for the RFLO, high-side injection is used for the GSM 850 and E-GSM 900
bands, and low-side injection is used for the DCS 1800 and PCS 1900 bands. The I and Q signals are
automatically swapped when switching bands. Additionally, the SWAP bit in register 03h can be used to
manually exchange the I and Q signals.
Low-pass filters before the OPLL phase detector reduce the harmonic content of the quadrature modulator
and feedback mixer outputs. The cutoff frequency of the filters is programmable with the FIF[3:0] bits in
register 04h (Figure 3-3), and should be set to the recommended settings detailed in the register
description.

3.2 PAM (SKY77328)

RF input and output ports of the SKY77328 are internally matched to a 50 Ω load to reduced the number of
external components for a quad-band design. This chip contains band-select switching circuitry to select
GSM (logic 0) or DCS/PCS (logic 1) as determined from the Band Select (BS) signal. The BS pin selects the
PA output (DCS/PCS out or GSM850/900 out) and the Analog Power Control (VAPC) controls the level of
output power.

Figure. 3-4

3. TECHNICAL BRIEF

- 28 -

3.3 26 MHz Clock (VCTCXO)

The 26 MHz clock(X501) consists of a TCXO(Temperature Compensated Crystal Oscillator) which
oscillates at a frequency of 26 MHz. It is used within the Si4210, analog base band chipset (U100, AD6535),
digital base band chipset (U101, AD6527)

3.4 Power Supplies for RF Circuits (RF LDO)

Two regulators are used for RF circuits. One is MIC5255 (U504), and the other is one port of AD6535
(U100).
MIC5255 (U504) supplies power to transceiver (SI4210, U502). One port of AD6535 supplies power to
VCTCXO (X501). Main power (VBAT) from battery is used for PAM (SKY77328, U501) because PAM
requires high power.

(AFCDAC)

4

VCONT

1

26MHz

X501

2

GND

3

OUT

VCC

15K

R523

C548

1000p

2V75_VVCXO

C549

2.2u

AFC

Figure 3-5 VCTCXO CIRCUIT DIAGRAM

Supplier Voltage Powers Enabled signal

U504(VRF) 2.85 V U502 CLKON

U100(VVCXO) 2.75 V X501

Battery(VBAT) 3.4 ~ 4.2 V U501, U504

Table 3-2 RF POWER SUPPLIERS

26MHz

3. TECHNICAL BRIEF

- 29 -

Figure 3-6. RF LDO CIRCUIT DIAGRAM

CLKON

VBAT

U504

MIC5255-2.85BM5

BYP

5

43

C547

0.01u

C545
27p

C546
1uF

IN1OUT

2

GND
EN

2V85_RF

C543

4.7u

C544
27p

3. TECHNICAL BRIEF

- 30 -

3.5 Digital Main Processor (AD6527B)

Figure 3-7. SYSTEM INTERCONECTION OF AD6527 EXTERNAL INTERFACE

3. TECHNICAL BRIEF

- 31 -

• AD6527 is an ADI designed processor.

• AD6527 consists of

1. Control Processor Subsystem

• 32-bit ARM7TDMI Control Processor

• 58.5 MHz operation at 1.7V

• On-board 16KB instruction/Data Cache

• 1 Mbits of on-chip System SRAM

2. DSP Subsystem

• 16-bit Fixed Point DSP Processor

• 91 MIPS at 1.7V

• 16K word Data and 16K word Program SRAM

• 4K word Program Instruction Cache

• Architecture supports Full Rate, Enhanced Full Rate, Half Rate, and AMR Speech
Encoding/Decoding Algorithms

3. Peripheral Subsystem

• Shared on-chip peripheral and off-chip interface:

• Support for Burst and Page Mode Flash

• Support for Pseudo SRAM

• Ciphering module for GPRS supporting GAE1 and GAE2 encryption algorithms

• Parallel and Serial Display Interface

• 8 x 8 Keypad Interface

• Four independent programmable backlight plus One Service Light

• 1.8V and 3.0V, 64 kbps SIM interface

• Universal System Connector Interface

• Slow, Medium and Fast IrDA transceiver interface

• Enhanced Generic Serial Port

• Dedicated SPI interface

• Thumbwheel Interface

• JTAG Interface for Test and In-Circuit Emulation

4. Other

• Supports 13 MHz and 26 MHz Input Clocks

• 1.8V Typical Core Operating Voltages

• 204-Ball LFBGA(mini-BGA) Package

5. Applications

• GSM900/DCS1800/PCS1900/PCS850 Wireless Terminals

• GSM Phase 2+ Compliant

• GPRS Class 12 Compliant

• Multimedia Services(MMS)

• Extended Messaging System(EMS)