LG KG110 Service Manual

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edoM KG110/KG115/MG110a/MG110b

Service Manual

KG110/KG115/

MG110a/MG110b

P/N : MMBD0061701 Date : Aug 2006 / Issue 1.0

KG110_Cover_Eng 2006.8.9 3:57 PM Page 1

1. INTRODUCTION ......................................................................................................................3

1.1 Purpose ....................................................................................................................................3

1.2 Regulatory Information..............................................................................................................3

A. Security ..................................................................................................................................3

B. Changes in Service ................................................................................................................3

C. Maintenance Limitations ........................................................................................................3

D. Notice of Radiated Emissions ................................................................................................3

E. Interference and Attenuation ..................................................................................................4

F. Electrostatic Sensitive Devices................................................................................................4

2. SYSTEM SPECIFICATION......................................................................................................6

3. TECHNICAL BRIEF ................................................................................................................7

3.1 KG110 Block Diagram ..............................................................................................................7

3.2 RF Part Introduction..................................................................................................................8

3.2.1 Receiver Part......................................................................................................................8

A.Low Noise Amplifiers................................................................................................................9

B.Down-Converting Mixers..........................................................................................................9

C.Baseband Amplifiers / Low Pass Filters ................................................................................ 9

D.Baseband Output D.C. Offset Correction ..............................................................................10

E.Receiver Local Oscillator (LO) Generator..............................................................................10

3.2.2 Transmitter Part ..............................................................................................................10

A. Power Amplifier Module........................................................................................................11

B.Quadrature Modulator............................................................................................................11

C.Phase Frequency Detector (PFD) ........................................................................................12

D.Loop filter ..............................................................................................................................12

E.TX VCO..................................................................................................................................12

F.Feedback Down-Converting Mixer ........................................................................................12

G.Transmit Frequency Plan ......................................................................................................12

H.Main Frequency Synthesizer ................................................................................................12

I.Fractional N Dividers ..............................................................................................................13

J.Phase Frequency Detector/Charge Pump..............................................................................13

K.Synthesizer Loop filter ..........................................................................................................13

L.Voltage Controlled Oscillator ..................................................................................................13

3.2.3 The Crystal Reference System ........................................................................................13

3.2.4 Power Management ........................................................................................................14

A.LDO Usage............................................................................................................................14

3.3 Baseband Introduction ............................................................................................................15

3.3.1 Baseband Processor (AD6720 , U101) ............................................................................15

3.3.2 Interconnection with external devices ..............................................................................15

A. RTC block interface ..............................................................................................................15

B. LCD module interface ..........................................................................................................16

C. RF interface..........................................................................................................................16

D. SIM interface ........................................................................................................................17

Table Of Contents

1

E. LDO Block ............................................................................................................................18

3.3.3 Battery Charging Block ....................................................................................................18

3.3.4 Display and Interface ......................................................................................................20

3.3.5 Keypad Switches and Scanning ......................................................................................21

3.3.6 Microphone...................................................................................................................... 22

3.3.7 Soft-midi and Main Speaker ............................................................................................23

3.3.8 Headset Interface ............................................................................................................24

3.3.9 Key Back-light Illumination ..............................................................................................25

3.3.10 LCD Back-light Illumination............................................................................................26

3.3.11 VIBRATOR......................................................................................................................26

4. Trouble shooting..................................................................................................................28

4.1 RF components ......................................................................................................................28

4.2 RX Trouble..............................................................................................................................29

4.2.1 Check Crystal Circuit........................................................................................................30

4.2.2 Check Control Signal ......................................................................................................31

4.2.3 Check Mobile SW & ANT SW ..........................................................................................32

4.2.4 Check SAW filter..............................................................................................................34

4.2.5 Check I/Q signal ..............................................................................................................35

4.3 TX Trouble ..............................................................................................................................36

4.3.1 Check Crystal Circuit ......................................................................................................37

4.3.2 Check Control Signal ......................................................................................................38

4.3.3 Check TX I/Q signal ........................................................................................................39

4.3.4 Check PAM control signal ................................................................................................40

4.3.5 Check Mobile SW & ANT SW ..........................................................................................41

4.4 Power On Trouble ..................................................................................................................43

4.5 Charging Trouble ....................................................................................................................45

4.6 Download ..............................................................................................................................47

4.7 Calibration ..............................................................................................................................49

4.7.1 Equipment Setup ..............................................................................................................49

4.7.2 Setup................................................................................................................................49

4.8 LCD Trouble............................................................................................................................56

4.8.1 LCD Blue Screen or abnormal display ............................................................................56

4.8.2 LCD Black Screen............................................................................................................57

4.9 Receiver Trouble ....................................................................................................................58

4.10 Speaker Trouble ....................................................................................................................61

4.11 MIC Trouble ..........................................................................................................................63

4.12 Earphone Trouble..................................................................................................................65

4.13 KEYPAD Backlight LEDS Trouble ........................................................................................68

4.14 SIM Trouble ..........................................................................................................................69

5. Appendix ..............................................................................................................................71

1. BOM..........................................................................................................................................71

2. Exploded View ..........................................................................................................................80

3. Circuit diagram..........................................................................................................................82

4. Pcb layout..................................................................................................................................86

2

3

3

1. INTRODUCTION

1.1 Purpose

This manual provides the information necessary to repair, calibration, description and
download the features of KG110.

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. 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.

C. 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.

D. 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.

1. INTRODUCTION

1. INTRODUCTION

4

E. Interference and Attenuation

Phone may interfere with sensitive laboratory equipment, medical equipment, etc.
Interference from unsuppressed engines or electric motors may cause problems.

F. Electrostatic Sensitive Devices

1. INTRODUCTION

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.

5

2. SYSTEM SPECIFICATION

2. SYSTEM SPECIFICATION

6

Item Target Specification

Form Factor Bar Type

Standard Battery (830mAh , Li-ion)

Size : 34(W) X 50(H) X 4.5(T) mm

Weight: 20g

Size 102.8 X 44 X 16.5mm

Weight 71 Gram(with standard battery)

Standby Current Below 3.0 mA under the least current consumption

(e.g. Paging Period = 9)

Talk Time Up to 3 hrs (GSM Tx Lev:5)

Standby Time Up to 200 hrs : Paging Period 9, RSSI 85dBm

Antenna Internal

LCD Main LCD: CSTN 128° X 128 Pixels 65K Color

Back Light Blue LED

PC Sync No
Indicator LED None

Vibrator Yes (Cylinder Type)

Buzzer Yes

C-MIC Yes

Receiver Yes

Earphone Jack Optional

SIM Socket Yes (SIM Block Type)

Volume Key No

Voice Key No
MP3/AAC No

MIDI 40 Poly Software MIDI

I/O Connector 24Pin

Basic Accessory Travel Adaptor

3. TECHNICAL BRIEF

3. TECHNICAL BRIEF

3.1 KG110 Block Diagram

Figure 3-1: KG110 Top Level Block Diagram

The Figure 3-1 shows the top level block diagram of KG110, it contains RF and BB part.
The following list is the detailed:

1. AD6720 : ADI baseband chipset,

including Digital Base Band (DBB) and Analog Base Band ABB

2.TQM6M4003 : Triquint PAM and Ant Switch

3. Transceiver : ADI Othello G AD6548

4. Flash: Spansion 128Mbit : 32Mbit

5. Others:

A. 22 keys
B. 128 x 128 65K CSTN –LCD module
C. Vibrator
D. Mic
E. Speaker and receiver
F. Ear-jack
G. Sim socket
H. Battery connector

7

Key Pad

24 Pin I/O Connector

Power

830mAh

Li-Ion

PAM + FEM

(TQM6M4003)

32.768k XTAL

Serial Port

BB Chip
AD6720

LCD(65K)

Main 1.5”

Audio AMP

MAX9718

(Including

DBB and ABB)

Charging
Circuit

TRANSCEIVER

Othello G

Vibrator

Ear Mic

MIC

Circuit

Spansion

128Mbit Nor

+ 32M SRAM

Memory Parallel
Interface

Analog
Switch

SIM

SIM

Speaker/RCV

MIC

3. TECHNICAL BRIEF

3.2 RF Part Introduction

The RF parts consists of a transmitter part, a receiver part, a voltage supply part,
the crystal reference system. And the main RF Chipset AD6548 is a highly integrated
direct conversion radio solution that combines, on a single chip, Quad Band Radio
(GSM850,E-GSM,DCS1800 and PCS1900 and power management functions necessary
to build the most compact GSM radio solution possible. This quad-band GSM transmit module
integrates a PA, a low-pass filter, a linear Tx / Rx switch along with PA and switch control
combined with ESD protection circuitry in one module,.

3.2.1 Receiver Part

The Receiver part in AD6548 contains all active circuits completely, full receiver chain
with the exception of discrete front-end RF SAW filters. The AD6548 uses direct
conversion receiver architecture of the OthelloTM family. For Quad band applicationsthe front
end features four fully integrated programmable gain differential LNAs. The RF is then
downconverted by quadrature mixers and then fed to the baseband programmable-gain
amplifiers and active filters for channel selection. The Receiver output pins can be directly
connected to the baseband analog processor. The Receive path features automatic calibration
and tracking to remove DC offsets. The RF Receiver block is shown as below.

8

3. TECHNICAL BRIEF

Figure 3-2: The RF Receiver Block

9

A. Low Noise Amplifiers

The AD6548 includes four fully integrated Low Noise Amplifiers (LNAs), to support quad band
applications without further external active components. The LNAs have differential inputs
which minimize the effect of unwanted interferers. The inputs are easily matched to industry
standard FEMs or discrete Rx SAW filters. The outputs of the LNAs are directly coupled to the
down-converting mixers. The voltage gain of the LNAs are typically 24 dB. Each LNA can be
switch to a low gain mode when receiving large input signals as part of the AGC system.

B. Down-Converting Mixers

Two quadrature mixers are used to mix down the signals from the LNAs, one for the
high bands (1800 and 1900 MHz) and one for the low bands (850 and 900 MHz).
The outputs of the mixers are connected to the baseband section through an integrated
single pole filter with nominal cut-off frequency of 800kHz. This acts as a “roofing filter”
for the largest blocking signals (i.e. those 3MHz) and prevents the baseband amplifiers
from being overloaded.

C. Baseband Amplifiers / Low Pass Filters

The baseband amplifiers provide the majority of the analog receiver gain.
The filtering is provided by an integrated 5th order Chebyshev filter giving the necessary adja­cent channel and blocking filtering, it is also acting as an anti-alias filtering for Baseband IC’s
converters. Afinal low pass pole is possible at each of the baseband outputs via internal series
resistor along with an external shunt capacitor.

EGSM/GSM850 In

TX RF Input

Vmod_en

Vramp

Vbatt

Vtx

Vbs2

Vbs1

DCS/PCS In
TX RF Input

Logic

Power

Control

VCC_TXVC

O

ANT

TXOP_HI

/2

ANT

TXOP_LO

TX RF Output

RX RF Input

VCC_FE
ESD­Diode

&

Vcc1

V1

Vcc2

(Internal Voltage)

SDATA

SCLK

RX850

RX850B
RX900

RX900B

RX1800

RX1800B

RX1900

RX1900B

SEN

LNA Gain Reduction

Generator

TX_LO
TX_LO1

2

Generator

Serial

Interface

RX LO

TX LO

Band

Control

TX circuits

Supply

LDO

Reg 3

TX Loop filter

PHD

Tx_LO1

DC Offset
Correction
DC Offset
Correction

Frac-N Synth VCTCXO

LO VCO

Supply

LDO
Reg 2

General
Supply

LDO

Reg 1

Supply

TXIB

TXI

I

IB

RX

I

/4

Tx_LO2

Ref

RXIB

VCC_BBI

VCC_BBQ

Q

TXQ

QB

RXQB

VAFC

AFC

REFINB

REFIN

REF_OP

REF_OP

VCC_REF

CLK

TX

Q

B
A

B

S

RX

E

Q

B
A
N
D

VDD

3. TECHNICAL BRIEF

The external capacitor is not required with ADI baseband ICs. The on chip filter has an auto
calibration feature ensuring that the filters are tuned for optimum performance. The baseband
amplifiers have programmable gain for system AGC.
A total of 57 dB of gain control is provided in 3dB steps programmable over the serial
interface. This together with the LNA gain control gives a total of 77dB of gain control range.
The receive baseband outputs are routed to the common Rx/Tx I/Q ports for connection with
the baseband converters.

D. Baseband Output D.C. Offset Correction

In order to minimize D.C. offsets inherent in the receiver and maximize dynamic range
a D.C offset correction circuit is integrated. This correction is triggered over the serial bus
and then an offset tracking loop is enabled to minimize residual offsets under all conditions.
The tracking loop is fully hardware integrated, requiring no software intervention.

E. Receiver Local Oscillator (LO) Generator

The Rx LO generator is used to avoid DC offset problems associated with LO leakage
into the receiver RF path. By operating the VCO at a frequency other than the desired
receive frequencies,any leakage of the VCO (e.g. via package) will fall out of band.
The LO generator is used to convert the offset synthesized VCO output to the
on-frequency quadrature LO required by the chipset.
The LO generator is implemented as a regenerative frequency divider, performing a 2/3
multiplication of the VCO output for the high band (DCS1800/PCS1900) and a 1/3
multiplication for low band (E-GSM/GSM850).

3.2.2 Transmitter Part

The Transmitter part contains AD6548 active parts and PAM .
The transmit section of the AD6548 radio implements a translation loop modulator.
This consists of a quadrature modulator, high speed phase-frequency detector (PFD) with
charge pump output, loop filter, TX VCO and a feedback down converting mixer.
The VCO output (divided by 2 for low band) is fed to the power amplifier with a portion
internally fed back into the down-converting feedback mixer to close the feedback loop.

10

3. TECHNICAL BRIEF

A. Power Amplifier Module

11

Figure 3-3: Power Amplifier Module

Table 3-1: PAM Truth Table

The advanced quad-band Transmit Module designed for mobile handset applications
provides full RF transmit functionality.The GSM850/900 and DCS/PCS power amplifier
blocks including power control are combined with the low insertion loss quad-band
pHEMT switch, Tx harmonics filtering, integrated switch decoder, four receive ports,
and full ESD protection. This architecture eliminates the need for any PA-to-switch design
effort for phone designers. All four Rx ports are frequency independent and allow flexible
routing to the transceiver. Fabricated in high-reliability InGaP HBT / pHEMT technology, the
module supports GPRS class 12 operation and provides 50 Ohms input and output
impedances at all RF input and output ports. The module control inputs are CMOS
compatible and has no need for an external reference voltage. With its excellent efficiency
performance in all 4 bands, the power amplifier and switch module contributes to the overall
talktime targets of next generation mobile handset designs.

B. Quadrature Modulator

The Quadrature modulator takes the baseband I & Q signals and translates these into a GMSK
signal at the Transmit Intermediate Frequency (TX IF). After bandpass filtering and limiting the
TX IF signal is used as the reference input to the Phase Frequency Detector (PFD) of the
transmit PLL.

Operating

Mode

TX GSM 850/900

TX DCS/PCS

RX1

RX2

RX3

RX4

Sleep Mode

Vmod_en Vtx Vbs1 Vbs2

H H L L

H H H L

H L L L

H L L H

H L H L

H L H H

L L L L

Control Voltage

3. TECHNICAL BRIEF

C. Phase Frequency Detector (PFD)

The PFD ensures that the transmitted signal contains the required modulation and is
accurately locked to the desired GSM channel. The downconverted feedback signal from
the TXVCO and the Quadrature Modulator output are phase compared by the PFD.
The PFD charge pump generates a current pulse proportional to the difference in phase
which is applied to the loop filter.

D. Loop filter

To minimize complexity of the external PCB layout the TX loop filter is fully integrated into
the IC. At power up the filter is automatically calibrated as part of the baseband filter cal,
eliminating process tolerances. The calibration is fully integrated and requires no
extra programming.

E.TX VCO

The Transmit Voltage Controlled Oscillator (TX VCO) and tank components are a fully
integrated subsystem. The subsystem includes PA drivers so the outputs are used to directly
drive the external PAs. The low noise oscillator design and internal filtering mean that external
TX SAW filters are not required. In Low band operation the TX VCO output is divided by two
and filtered. The TX VCO is automatically calibrated to ensure optimum performance over its
operating frequency of 1648 to 1910 MHz.

F. Feedback Down-Converting Mixer

The feedback down converting mixer is used to translate the TX VCO output frequency to
the TX IF. An integrated band pass filter exists between the mixer and the PFD to filter the
mixers unwanted side band and higher order mixing products.

G.Transmit Frequency Plan

Unlike many other translation loop modulators the AD6548 uses only a single VCO source to
derive the local oscillator signal for both the Feedback Down-Converting Mixer and the
Quadrature modulator. Therefore there is a fixed relationship between the Tx IF frequency and
the LO VCO frequency .This ratio was chosen to minimize VCO tuning range, TX IF frequency
variation and ensure excellent transmit spectral mask performance. The Feedback-Down
Converting Mixer operates low side injection for the high bands and high side injection for the
low bands. The final relationship between the transmitted TX frequency frequency and the LO
VCO frequency is different between the two bands. These relationships are taken account of in
the synthesizer architecture and programming.

H. Main Frequency Synthesizer

The AD6548/9 has a single fast-locking fractional synthesizer used for VCO control in both
receive and transmit mode. The entire system including VCO, tank, fractional N dividers,
sigma delta compensation, charge pump and loop filters are fully integrated.
The only external component is a low cost crystal for the reference.
The synthesizer is controlled via the serial interface. The VCO is fed into the respective
dividers to generate the appropriate LO frequencies for the RX and TX bands.

I. Fractional N Dividers

The fractional N divider allows the PLL system to have a smaller step size than the
comparison frequency which is set by the external reference to 26 MHz.
This feature allows all the GSM frequency band rasters to be achieved, with fast lock times
and good phase noise characteristics. The divider section consists of a dual modulus 8/9

12

3. TECHNICAL BRIEF

prescaler, integer M & A dividers, and fractional N system based on sigma-delta modulation
to generate the required fractional divide ratio. The Denominator of the fractional divider can
be set to 3 different values, (1040, 1170, 1235), depending on the mode of operation.
For example a denominator of 1040 with an input fraction F maintains an average value of
F/1040 allowing 25 kHz steps when operated at a reference of 26 MHz.

J. Phase Frequency Detector/Charge Pump

A Phase Frequency Detector (PFD) is used for the PLL phase detector.
The charge pump is designed such that good matching of up and down currents is
achieved over a wide output operating range. The charge pump output is internally routed to
the integrated synthesizer loop filter.

K. Synthesizer Loop filter

To minimize complexity of the external PCB layout the Main Synthesizer loop filter
is also fully integrated into the IC. No external components or adjustments are required .

L.Voltage Controlled Oscillator

The integrated voltage controlled oscillator (VCO) is a complete self-calibrating
subsystem. This employs a fully automated digital self-calibration function to
ensure optimum phase noise performance over the entire frequency range.
The VCO generates frequencies between 2520MHz and 2985MHz as required to operate in
the four bands for RX and TX.

3.2.3 The Crystal Reference System

The AD6548 requires only an external low cost crystal as the frequency reference.
The circuitry to oscillate the crystal and tune its frequency is fully integrated.
The Oscillator is a balanced implementation requiring the crystal to be connected
across 2 pins. There is a programmable capacitor array included for coarse tuning
of fixed offsets (e.g. crystal manufacturing tolerance), and an integrated varactor for
dynamic control. The oscillator is designed for use with a 26MHz crystal.
The crystal is connected as shown in figure.

13

Figure 3-4: The Crystal Reference System

Dedicated control software ensures excellent frequency stability under all
circumstances.

VAFC

AFC

REFINB

VCTCXO

Supply

Ref

REFIN

REF_OP

CLK

REF_OP

VCC_REF

3. TECHNICAL BRIEF

3.2.4 Power Management

For direct battery supply connect, and to reduce external circuitry complexity the AD6548/9
features three Low Drop Out Regulators (LDOs). The three LDOs provide isolation of the
oscillators and sensitive circuits from unwanted power supply and cross coupled noise.
They also ensure the IC operation is robust over a wide range of power supply voltages.
For power management the LDOs are independently controlled via the 3 wire serial bus.

A.LDO Usage

The following table describes the LDO usage:

14

LDO1 LDO2 LDO3

Rx and Tx baseband Main VCO TX VCO

sections

LDO OP External Connection

VLDO1 VCC_FE, VCC_BBI, VCC_BBQ
VLDO2 No external Connections, except for decoupling
VLDO3 No external Connections, except for decoupling

Table 3-2: Intended LDO Use

Table 3-3: LDO Connections

The LDO outputs require external connection to the respective pins described in table 3, and
each requires decoupling capacitors.The LDOs are designed to be unconditionally stable
regardless of the capacitor's ESR.

LDO1 derives its input references from the crystal supply voltage (VCC_REF).
It is therefore expected that VCC_REF be supplied from a external LDO of nominal supply
voltage 2.75V

(e.g. ADP3330 or Analog Baseband IC: Vout=2.75V 1.4%)

3. TECHNICAL BRIEF

3.3 Baseband Introduction

3.3.1 Baseband Processor (AD6720 , U101)

• AD6720 is an ADI designed processor

• AD6720 consists of

1. Control Processor Subsystem including:

• 32-bit MCU ARM7TDMI Control Processor

• 39 MHz operation at 1.8V

• 1Mb of on-chip System SRAM Memory

2. DSP Subsystem including:

• 16-bit Fixed Point DSP Processor

• 91 MIPS at 1.8V

• Data and Program SRAM

• Program Instruction Cache

• Full Rate, Enhanced Full Rate and Half Rate

• Speech Encoding/Decoding

• Capable of Supporting AMR & PDC Speech Algorithms

3. Peripheral Functions

• Parallel and Serial Display Interface

• Keypad Interface

• Flash Memory Interface

• Page-Mode Flash Support

• 1.8V and 3.0V, 64 kbps SIM Interface

• Universal System Connector Interface

• Data Services Interface

• Battery Interface (e.g. Dallas)

4. Other

• Supports 13 MHz and 26 MHz Input Clocks

• 1.8V Typical Core Operating Voltages

• 289-Ball Package (12x12mm) , 0.65mm Ball pitch

5. The AD6720 baseband transmit section supports the following

• mobile station GMSK modulation power classes:

• GSM 900/850 power classes 4 and 5,

• DCS 1800 power classes 1 and 2, and

• PCS 1900 power classes 1 and 2

15

3. TECHNICAL BRIEF

3.3.2 Interconnection with external devices

A. RTC block interface

Countered by external X-TAL
The X-TAL oscillates 32.768KHz

B. LCD module interface

16

Signals Description

L_MAIN_LCD_CS MAIN LCD driver chip enable.

LCD_RESET This pin resets LCD module.

LCD_WR Enable writing to LCD Driver.

LCD_RD Enable reading to LCD Driver.
LCD_RS This pin determines whether the data to LCD module

data or control data.

A1 Select 16bits interface mode for MAIN LCD.

Signals Description

LCD_LED_CTL Control LCD backlight level in 4 steps

DISP_LIGHT Current source for backlight LED

Signals Description

PA_BAND (GPO17) PAM Band Select
ANT_SW1 (GPO9)Antenna switch Band Select
ANT_SW2 (GPO11) Antenna switch Band Select

RF_PWR_DWN(GPO 4) Power down Input

CLKON RF LDO Enable/Disable

Table 3-4: LCD Pin Description

Table 3-5. Description Of LCD Backlight LED Control

The backlight of LCD module is controlled by AD6720 via AAT3110 , U300.
The control signals related to Backlight LED are given bellow.

C. RF interface

The AD6720 control RF parts through PA_BAND, ANT_SW1, ANT_SW2, ANT_SW3 ,
CLKON ,PA_EN, S_EN, S_DATA, S_CLK, RF_PWR_DWN.

3. TECHNICAL BRIEF

D. SIM interface

The AD6720 provides SIM Interface Module. The AD6720 checks status periodically
during established call mode whether SIM card is inserted or not, but it doesn't check
during deep Sleep mode. In order to communicate with SIM card, 3 signals SIM_DATA,
SIM_CLK, SIM_RST(GPIO_23) are required.
The descriptions about the signals are given by bellow Table 3-7 in detail.

17

Signals Description

PA_EN (GPO16) PAM Enable/Disable

S_EN (GPO19) PLL Enable/Disable

S_DATA (GPO20) Serial Data to PLL

S_CLK (GPO21) Clock to PLL

Signals Description

SIM_DATA This pin receives and sends data to SIM card.

This model can support only3.0 volt interface SIM card.
SIM_CLK Clock 3.25MHz frequency.
SIM_RST Reset SIM block(GPIO_23)

Table 3-6. RF Control Signals Description

Table 3-7: SIM Control Signals Description

3. TECHNICAL BRIEF

E. LDO Block

There are 8 LDOs in the AD6720.

- VCORE : supplies Digital base band Processor core and AD6720 digital core

- VMEM : supplies external memory and the interface to the external memory on the digital
base band processor (1,8V or 2.8V, 150mA)

- VEXT : supplies Radio digital interface and high voltage interface (2.8V, 170mA)

- VSIM : supplies the SIM interface circuitry on the digital processor and SIM card (2.85V,
20mA)

- VRTC : supplies the Real-Time Clock module (1.8 V, 20 mA)

- VABB : supplies the analog portions of the AD6720

- VMIC : supplies the microphone interface circuitry (2.5 V, 1 mA)

- VVCXO : supplies the voltage controlled crystal oscillator ( 2.75 V, 10 mA)

3.3.3 Battery Charging Block

1. It can be used to charge Lithium Ion batteries.

Charger initialization, trickle charging, and Li-Ion charging control are implemented
in hardware.

2. Charging Process

- Check charger is inserted or not

18

Figure 3-5: SIM Interface of AD6720

SIMDATAOP

VSIM

C326 NA

R341

20K

VSIM

C321

(1608)

J300

SCK-6S-12PT-TF

5

GND

6

VPP

7

IO

VCC

RST
CLK

1

2
3

C327 220n

C328 NA

2.2u

C329 1000p

R345 0

SIMRESET
SIMCLK

3. TECHNICAL BRIEF

- If AD6720 detects that Charger is inserted, the CC-CV charging starts.

- Exception : When battery voltage is lower than 3.2V, the precharge
(low current charge mode) starts firstly.

- And the battery voltage reach to 3.2V the CC-CV charging starts.

3. Pins used for charging

- VCHG : charger supply.

- GATEDRIVE : charge DAC output

- ISENSE : charge current sense input

- VBATSENSE : battery voltage sense input.

- BATTYPE : battery type identification input

- REFCHG : voltage reference output

4. TA (Travel Adaptor)

- Input voltage: AC 85V ~ 260V, 50~60Hz

- Output voltage: DC 5.2V ( 0.2 V )

- Output current: Max 800mA ( 50mA )

5. Battery

- Li-ion battery (Max 4.2V, Nom 3.7V)

- Standard battery: Capacity - 830mAh

19

PRECHARGE

R348

PRE_CHARGE

20K

C322

1U

VCHARGE VBAT

R342

33

R266

NA

3

2 5

1 6

R344

1K

4

R349

100K

Q300

UMX1NTN

3. TECHNICAL BRIEF

3.3.4 Display and Interface

• Main LCD

Controlled by L_MAIN_LCD_CS, LCD_RESET, LCD_RS, LCD_WR, LCD_RD, LCD_ID,
L_DATA[00:15] ports

• L_MAIN_LCD_CS : MAIN LCD driver chip enable. MAIN LCD driver IC has own CS pin

• LCD_RST : This pin resets LCD module. This signal comes from AD6720 directly.

• LCD_RS: This pin determines whether the data to LCD module are display data or control
data.

• L_WR : Write control Signal

• L_RD : Read control Signal. But this pin used only for debugging.

• L_DATA[00:15] : Parallel data lines.

• LCD_ID: LCD type selection signals

• For using 65K color, data buses should be 16 bits.

Properties Spec. Unit

Active Screen Size 35.78*40.05*2.8 mm
Color Depth 65,536 colors
Resolution 128 X RGB X 128 dots

20

Figure 3-6: Circuit For Battery Charging

C150

4.7u

VCHARGE

D100

CUS02

C129

R107 330

5

S

6

D4

7

D5

8

D6

Q100

TPCF8102-TE85L-F

D3
D2
D1

VBAT

R105

1u

G

0.2

(1%)

4

3
2
1

VRTC

R106

NA

C131

NA

KEYBOAR D_BACKLIGH T

C127

0.1u

BATT_TEMP

DISP_LI GHT

HOOK_DETECT

ASM

LIGHT1
LIGHT2

R108 82K

(1%)

R111 0

R122 0

C126 1u

C128 1u

C134

0.1u

R10
F14
H13
J15

P8

R5
T12
D17
C15
C14
A13
A14
B14
T13
C12
A12
C13
B13
F17
B12

GPO_5
LIGHT1
LIGHT2
LIGHT3

GPO_22
GPO_23
VMEMSEL
REF
REFOUT
TEMP1
TEMP2
AUXADC1
AUXADC2
VRTC
VCHG
GATEDRIVE
ISENSE
VBATSENSE
REFCHG
BATTYPE

3. TECHNICAL BRIEF

3.3.5 Keypad Switches and Scanning

The key switches are metal domes, which make contact between two concentric pads on
the keypad layer of the PCB when pressed. There are 21 switches, connected in a matrix of
5 rows by 5 columns and additional GPIO 35 for KEY_ROW5, as shown in Figure 3-x,
except for the power switch (KB1), which is connected independently. Functions, the row
and column lines of the keypad are connected to ports of AD6720. The columns are outputs,
while the rows are inputs and have pull-up resistors built in. When a key is pressed,
the corresponding row and column are connected together, causing the row input to go low
and generate an interrupt. The columns/rows are then scanned by AD6720 to identify the
pressed key.

21

Figure 3-7: LCD Interface Circuit

_LCD_RESET

DATA0
DATA1
DATA2

DATA3
DATA4
DATA5
DATA6

DATA7
ADD1

_LCD_C S

_WR

DATA8
DATA9
DATA10
DATA11

DATA12
DATA13
DATA14
DATA15

LCD CONNECT ER

9
8
7
6

9
8
7
6

9
8
7
6

FL302

ICVE21054E250R4 01FR

INPUT_B1

INPUT_A1

INPUT_B2

INPUT_A2

INPUT_B3

INPUT_A3

INPUT_B4

INPUT_A4

G15G2

10

FL302

ICVE21054E250R4 01FR2

INPUT_B1

INPUT_A1

INPUT_B2

INPUT_A2

INPUT_B3

INPUT_A3

INPUT_B4

INPUT_A4

G15G2

10

FL302

ICVE21054E250R4 01FR4

INPUT_A1

INPUT_B1
INPUT_B2

INPUT_A2

INPUT_B3

INPUT_A3

INPUT_B4

INPUT_A4

G15G2

10

1
2
3
4

4

INPUT_A4

3

INPUT_A3

2

INPUT_A2

1

INPUT_A1

ICVE21054E250R401F R1

1
2
3
4

ICVE21054E250R401F R3

9

INPUT_B1

8

INPUT_B2

7

INPUT_B3

6

INPUT_B4

1
2
3
4

FL302

10

G15G2

INPUT_B4
INPUT_B3
INPUT_B2
INPUT_B1

FL303

INPUT_A1
INPUT_A2
INPUT_A3
INPUT_A4

G15G2

VMEMVMEM

R301

51K

C301 1u

C302 1u

CN301

1
2
3

CN301

4
5
6
7
8

9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41

10

6
7
8
9

LCD_LED_CTL

LIGHT2
LIGHT1

1
2
3
4

R302 56

R303 56

_RD

LCD_ID

R343

0

R304 51K

3. TECHNICAL BRIEF

22

3.3.6 Microphone

The microphone is placed to the front cover and contacted to main PCB.
The audio signal is passed to AIN1P and AININ pins of AD6720.
The voltage supply VMIC is output from AD6720, and is a biased voltage for the AIN1P.
The AIN1P and AIN1N signals are then A/D converted by the voiceband ADC part of AD6720.
The digitized speech (PCM 8KHz ,16KHz) is then passed to the DSP section of AD6720 for
processing (coding, interleaving etc).

Figure 3-8: Keypad Switches and Scanning

VBAT

R200

SW20

POWER

SW1

10K

R209 680

NA

R215

SW2

KEYON

SW3

KEYPAD

SW4

SW20

KEY_C OL0

KEY_C OL1

KEY_C OL2

KEY_C OL3

KEY_C OL4

NA

NA

NA

NA

R217

R201

R202

R203

NA

R204

RIGHT

SW5

3

SW9

6

SW13

9

SW17

#

SW6

SW10

SW14

SW18

UP

2

5

8

0

LEFT

SW7

SW11

SW15

SW19

DOWN

SW8

1

4

7

*

MEN U

SW12

S2(OK)

SW16

SEND

SW21

SELECT

CLR

R211

R212

R213

R214

R216

R205 680

NA

R206 680

NA

R207 680

NA

R208 680

NA

R210 680

NA

KEY_ROW 0

KEY_ROW 1

KEY_ROW 2

KEY_ROW 3

KEY_ROW 4

3. TECHNICAL BRIEF

23

3.3.7 Soft-midi and Main Speaker

The TTPCom Embedded MIDI & Polyphonic Orchestra product, “TEMPO”, is a
complete MIDI music player solution offering the following features:

• MIDI-standards compliant

• MIDI files playable as polyphonic ringtones

• Low memory footprint - less than 8 kB internal MCU system RAM

• 40 notes polyphony

• Intelligent note-stealing algorithm ensures optimum use of available synthesiser
polyphony

• Open API enabling product differentiation via the addition of MIDI music support to
existing and new customer applications

• MIDI file parser supports Standard MIDI (formats 0, 1 and 2), SMAF-MA3, GM-Lite
and SP-MIDI

The main speaker is driven directly by AD6720 AOUT1P and AOUT1N pins
and the gain is controlled by the PGA in an AD6720.

Figure 3-9: Connection Between Microphone And AD6720

VMIC

VINN ORP

NNORN

C263

39P

CLOSE TO MIC

+

C261

C262

39P

10U

C264

39P

C266

39P

C267

39P

VA201

AVL5M02-200

R262

100

R263

100

R264

1K

R265

2.2K

R261

0

C265

0.1U

R266

2.2K

MIC 200

OB4-15L42-C33L

VA202

AVL5M02-200

3. TECHNICAL BRIEF

24

3.3.8 Headset Interface

This phone has 5 electrodes such as GND, AUXIP, ACK_DETECT, HOOK_DETECT.
This type supports mono sound.

Switching from Receiver to Headset Jack

If jack is inserted, JACK_DETECT goes from high to low.
Audio path is switched from receiver to earphone by JACK_DETECT interrupt.

Switching from Headset Jack to Receiver

If jack is removed, JACK_DETECT goes from low to high.
Audio path is switched from earphone to receiver by JACK_DETECT interrupt.

Hook detection

If hook-button is pressed, HOOK_DETECT is changed from low to high.
This is detected by AUXADC2.

And then hook is detected.

Figure 3-10: Main Speaker Circuit

A
A

SPK_P

SPK_N
MP_SHDN
MP_SHDM

R275 0
R276 0

VBAT

AUDIO

C280

1u

U202

MAX9718

9

4

IN+

2

IN-

1

SHDN

3

SHDM

OUT+

VCC

OUT­BIAS

NC

GND17GND2

11

R283 NA

R284 NA

10
6
5
8

C277

0.1u

RCV_P
RCV_N

SPK_RCV_P

SPK_RCV_N

VEXT

R280

10K

SP201

SPK_RCV_SEL

HIGH

LOW

R271 0
R272 0

SP202

C271

1u

U201

MAX4684EBC_T

B4

C273

39p

C2

IN1

V+

A2

IN2

C3

COM1

A3

COM2

GND

B1

C272

39p

C274

39p

C4

NO1

A4

NO2

C1

NC1

A1

NC2

SELECT

SPEAKER

RECEIVER

SPK_RCV_SEL

SPK_RCV_P
SPK_RCV_N

(FOR TUNI NG NOISE)

RC201

RC202

3. TECHNICAL BRIEF

25

3.3.9 Key Back-light Illumination

In key back-light illumination, there are 6 Blue LEDs in Main Board, which are driven by
KEY_BACKLIGHT signal from AD6720.

Figure 3-11: Headset Jack Interface

Figure 3-12: Key Backlight Illumination

KEY BACKLIGHT

(6 LIGHT)

VMEM

R232

0

C233

39P

VMICVMEM

C232

39P

1

OUT

EAR JACK

R239 0

C238

39P

VA203

AVL5M02-200

HOOK_DETECT

SP203

J200

5

1

3

4

2

VA204

AVL5M02-200

.

.

SP204

C231

39p

6

NC4NO

GND

2

VCC

IN

COM

5

U204
NLAST4599DFT2G

R238

NA

VMEM

3

1

R231

100K

R233

0

R235

NA

R236

1K

HEADSET_SPK_P

JACK_DETECT

HEADSET_MIC_P

VMIC_ON

VMIC_N VMEM VMEM

R237

+

C234

10u

2.2K

C235

39P

R234

1M

VIN-

4

-

VIN+

3

+

R240

510K

C236 10u R241 4.7

R242 0

R243 4.7

C237

39P

52

VCC

GND

U205
LMV7291MGX-NOPB

R244

33K

VBAT

C225 1u

LD206

220

R226

LEBB-S14H

C226 1u

LD201

LEBB-S14H

220

R221

C221 1u

LD202

LEBB-S14H

220

R222

C222 1u

LD203

LEBB-S14H

220

R223

C223 1u

LD204

LEBB-S14H

220

R224

C224 1u

LD205

LEBB-S14H

220

R225

KEYBOAR D_BACKLIGHT

3. TECHNICAL BRIEF

26

3.3.10 LCD Back-light Illumination

LCD backlight LEDs is controlled by AD6720 via AAT3110, U300.

3.3.11 VIBRATOR

The vibrator is placed in the folder cover and contacted to LCD MODULE.
The vibrator is driven from VIBRATOR (GPIO_0) of AD6720

Figure 3-13: Main LCD Backlight Illumination

CHARGE PUMP

VBAT

C324

10u

C325

1u

U300

AAT3110IGU-5_T1

6
5
4

C+
VIN
C-

VOUT

GND

_SHDN

1
2
3

C323

10u

FB301

R346 10

R347

NA

LCD_LED_CTL

DISP_LIGHT