3.4 26 26 MHz Clock (DCXO, X500). LG KG291, KG290

3. TECHNICAL BRIEF

3.4 26 26 MHz Clock (DCXO, X500)

The 26 MHz clock(X500) consists of a DCXO (Digital Compensated Crystal Oscillator) which oscillates at a frequency of 26 MHz. It is used within the AD6548, base band processor(AD6721,U103),

CAMERA( U400,AIT813G )

C519

0.1u

0.15MM

28

29

30

31

32

25

26

27

RX1900B

RX1900

RX1800B

RX1800

RX900B

RX900

RX850B

RX850

33

GND

U501

AD6548

VLDO2

VLDO1

VBAT

VDD

VCC_TXVCO

TXOP_HI

TXOP_LO

VLDO3

16

15

14

13

12

11

10

9

C531

0.1u

C521

27p

C541

39p

IP

IN

26MHz

X500

TSX-3225_26MHZ

4 3

1 2

Figure 3-3. DCXO CIRCUIT DIAGRAM

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Only for training and service purposes

3. TECHNICAL BRIEF

3.5 Baseband Processor (AD6721 , U103)

• AD6721 is an ADI designed processor

• AD6721 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[1] 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 AD6721 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

Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

- 21 LGE Internal Use Only

3. TECHNICAL BRIEF

Figure 3-4-1 SYSTEM INTERCONECTION OF AD6721 EXTERNAL INTERFACE

LGE Internal Use Only - 22 Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

3. TECHNICAL BRIEF

3.5.1 Interconnection with external devices

A. RTC block interface

Countered by external X-TAL

The X-TAL oscillates 32.768KHz

B. LCD module interface

The LCD module is controlled by CAMERA IC, AIT813G

If AIT701G is in the state of by-pass mode, the LCD control signals from AD6721 are by-passed through AIT813G.

In operating mode, the AIT813G controls the LCD module through L_MAIN_LCD_CS,

L_SUB_LCD_CS, LCD_RESET, LCD_RS, LCD_WR, LCD_RD, L_DATA[15-00], 2V85_VCAM,

IF_MODE, LCD_ID[1:3].

Signals

L_MAIN_LCD_CS

LCD_ID

LCD_RESET

LCD_WR

LCD_RD

LCD_RS

2V8_VLCD

IF_MODE

Description

MAIN LCD driver chip enable. MAIN LCD driver IC has own CS pin

Select LCD modoule maker(2.4V : HITACHI, 0V : LGIT)

This pin resets LCD module. This signal comes from AD6721 directly.

Enable writing to LCD Driver.

Enable reading to LCD Driver.

This pin determines whether the data to LCD module are display data or control data. LCD_RS can select 16 bit parallel bus.

2.8V voltage is supplied to LCD driver IC.

Select 16bits or 8bits interface mode for MAIN LCD.

For the future

Table 3-2 . LCD CONTRON SIGNALS DISCRIPTION

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Only for training and service purposes

- 23 LGE Internal Use Only

3. TECHNICAL BRIEF

The backlight of LCD module is controlled by AD6721 via AAT3155 , U603. The control signals related to Backlight LED are given bellow.

Signals

MLED

LCD_DIM_CTL

MLED[1:3]

Description

Current source for backlight LED

Control LCD backlight level in 16 steps

This pins are returned-paths for backlight LED current source (MLED)

Table 3-3. DESCRIPTION OF LCD BACKLIGHT LED CONTROL

C. RF interface

The AD6721 control RF parts through PA_BAND, ANT_SW1, ANT_SW2, ANT_SW3 , CLKON ,

PA_EN, S_EN, S_DATA, S_CLK

Signals

PA_BAND (GPO 17)

ANT_SW1 (GPO 9)

ANT_SW2 (GPO 10)

PA_EN (GPO 16)

S_EN (GPO 19)

S_DATA (GPO 20)

S_CLK (GPO 21)

PAM Band Select

Antenna switch Band Select

Antenna switch Band Select

PAM Enable/Disable

PLL Enable/Disable

Serial Data to PLL

Clock to PLL

Description

Table 3-4. RF CONTROL SIGNALS DESCRIPTION

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3. TECHNICAL BRIEF

D. SIM interface

The AD6721 provides SIM Interface Module. The AD6721 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 3-5 in detail.

Signals

SIM_DATA

SIM_CLK

SIM_RST

(GPIO_23)

Description

This pin receives and sends data to SIM card.

This model can support only 3.0 volt interface SIM card.

Clock 3.25MHz frequency.

Reset SIM block

Table 3-5. SIM CONTROL SIGNALS DESCRIPTION

2V85_VSIM 2V85_VSIM

SIM CONNECTOR

SIM_DATA

R235

15K

R236 0

C237

NA

J202

6

10

9

4

5

C5

C6

C7

C1

C2

C3

GND4 GND1

GND3 GND2

3

7

1

2

8

C236

220n

C238

NA

C239

1000p

SIM_RST

SIM_CLK

Figure 3-5. SIM Interface of AD6721

Copyright © 2007 LG Electronics. Inc. All right reserved.

Only for training and service purposes

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