Panasonic GD55 Service Manual

Personal Cellular Telephone

Supplement - 1

EB-GD55 EB-GD55C

ORDER NO. OMTD031202S8

Please file and use this simplified service manual together with the service manual for Model No. EB-GD55, Order No. ORDER NO. OMTD030201C8.

This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product. Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or repair the product or products dealt with in this service information by anyone else could result in serious injury or death.

WARNING

ç 2003 Panasonic Mobile Communications Co., Ltd.

distribution is a violation of law.

1. TECHNICAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

1.1. RF OVERVIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

1.1.1. General Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-1

1.1.2. Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.1.3. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2

1.1.4. Transceiver - - Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3

1.1.5. Transceiver - - Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1.2. BASEBAND OVERVIER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1.2.1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4

1.2.2. Digital Baseband Processor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5

1.2.3. Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6

1.2.4. Subcarrier Identity Module (SIM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7

1.2.5. UPU Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7

1.2.6. LCD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7

1.2.7. Real Time Clock (RTC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7

1.2.8. Audio System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-8

1.2.9. Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-10

1.3. POWER MANAGEMENT SUBSYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11

1.3.1. Power System Ship . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-11

1.3.2. Power Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12

1.3.3. Power On/Off Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12

1.3.4. Voltage Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-12

1.3.5. Battery Charging and Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-13

2. REPLACEMENT PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1

3. CIRCUIT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.1. Circuit Diagram-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1

3.2. Circuit Diagram-2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2

3.3. Circuit Diagram-3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3

3.4. Circuit Diagram-4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4

3.5. Circuit Diagram-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5

3.6. Circuit Diagram-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6

3.7. Circuit Diagram-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7

3.8. Circuit Diagram-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8

3.9. Circuit Diagram-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-9

4. LAYOUT DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-1

1. TECHNICAL DESCRIPTION

1.1. RF OVERVIEW

1.1.1. General Specifications

The telephone is a Tri-Band product. The transmit and receive bands for the mobile are given in the table below:

TX RX

E-GSM 900 880-915 MHz 925-960 MHz GSM 1800 1710-1785 MHz 1805-1880 MHz PCS 1900 1850-1910 MHz 1930-1990 MHz

Other salient technical features are as follows:

E-GSM 900 GSM 1800 PCS 1900

RX Bandwidth 35 MHz 75 MHz 60 MHz TX Bandwidth 35 MHz 75 MHz 60 MHz Number of Channels 174 374 299 AFRCN (Channel Numbers) 0- 124 512-885 512-810

975-1023

1st TX Channel 880.2 MHz 1710.2 MHz 1850.2 MHz

(Ch 975) (Ch 512) (Ch 512)

Last TX Channel 914.8 MHz 1784.8 MHz 1909.8 MHz

(Ch 124) (Ch 885) (Ch 810)

1st RX Channel 925.2 MHz 1805.2 MHz 1930.2 MHz

(Ch 975) (Ch 885) (Ch 512)

Last RX Channel 959.8 MHz 1879.8 MHz 1989.8 MHz

(Ch 124) (Ch 885) (Ch 810)

Maximum TX Power 33.0 dBm 30.0 dBm 30.0 dBm

(Class 4)(PL 5) (Class 1)(PL 0) (Class 1)(PL 0)

Minimum TX Power 5.0 dBm 0.0 dBm 0.0 dBm

(PL 19) (PL 15) (PL 15)

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1.1.2. Block Diagram

Figure 1.1. RF Block Diagram

1.1.3. Functional Description

■ Frequency plan

The TX frequency plan is shown below:

TX frequency plan TX frequency TX IF TX RF LO EGSM 900 880.2 MHz-914.8 MHz 88.46 MHz-114.35 MHz 1459.59 MHz-1543.725 MHz GSM 1800 1710.2 MHz-1784.8 MHz 90.316 MHz-104.776 MHz 1354.737 MHz-1414.482 MHz PCS 1900 1850.2 MHz-1909.8 MHz 97.379 MHz-112.341 MHz 1460.684 MHz-1516.606 MHz

Figure 1.2. Receiver block frequency plan

– 1–2 –

■ General

RF circuit design is built based on SKYWORKS-74017 direction conversion transceiver IC integrated by SAW filters, power amplifier with control circuit, and Transmitter/receiver switch. RF LO always requires external frequency sources with VCTCXO in EB-GD55. And LO frequency is periodically re-tuning to synchronize with cell or network.

■ Antenna

EB-GD55 uses Helical-type antenna, which is most low-cost, monopole-like antenna. The antenna takes different spacing to define bands of GSM, DCS and PCS.

1.1.4. Transceiver--Transmitter

Figure 1.3. Transmitter block diagram

– 1–3 –

1.1.5. Transceiver--Receiver

Figure 1.4. Receiver block diagram

RX path is a direction down conversion architecture that eliminates the need for Intermediate Frequency (IF) components. The device includes three bands integrated LNAS, a quadrate demodulator, baseband amplifier circuit with I/Q outputs and three stages of DC-offset correction. The DCOC correction loop ensures DC-offsets, generated in CX74017, do not overload baseband chain. The receiver can be calibrated to optimize IP2 performance, which ensures limited baseband interfering signal amplitude. The CX74017 also features an integrated, fully programmable, sigma-delta fraction-N synthesizer suitable for GPRS multi-slot operation

1.2. BASEBAND OVERVIEW

1.2.1. Introduction

The Baseband circuits of the phone are required to perform the following functions:

8 Equalization 8 Channel coding / decoding 8 Speech coding / decoding 8 Data Encryption 8 Layer 1, 2 and 3 software tasks 8 Man Machine interface (MMI) 8 System Interface 8 SIM Interface and Management 8 Audio and Tone Generation 8 Power supply and battery management 8 RF power control 8 Synchronization 8 Real time clock

– 1–4 –

Figure 1.5. Baseband Block Diagram

The EB-GD55 Baseband is built around a GSM chipset developed by Advanced Device. One chip (AD6522) carries out signal processing with DSP and CPU, and the other chip (AD6521) provides the analogue interface. The highly integrated nature of the chips means that each contains a large number of functions.

1.2.2. Digital Baseband Processor

GSM processor : ADI AD6522 Package : 160-Ball LFBGA Feature Complete single chip GSM Programmable Digital Baseband Processor divided into three main subsystems:

1. Control processor subsystem including 32-bit MCU ARM7TDMI control processor 39 MHz operation at 2.4 V 1Mb on-chip System SRAM Memory

2. DSP subsystem including 16-bit Fixed-out DSP Processor 65 MIPS at 2.4 V Data and Program SRAM Program Instruction Cache Full rate, Enhanced full rate and Half Rate Speech Encoding / Decoding

3. Peripheral Subsystem including Shared Peripheral Bus and Interface Peripherals

– 1–5 –

Figure 1.6. AD6522 Functional Block Diagram

1.2.3. Keypad

The Keypad has a 4 x 5 matrix, allowing 18 keys to be scanned. When a key being pressed, a keypad interrupt is generated. To find which key has been pressed, the software scans each column in turn and reads which row is active. Because of key bounce, the key press is confirmed twice at approximately 40-60 ms intervals.

KEYCOL_0 [2] KEYCOL_1 [2] KEYCOL_2 [2] KEYCOL_3 [2] KEYCOL_4 [2]

SW70 1

1 2

KEY [*]

SW70 6

1 2

KEY [0]

SW71 1

1 2

KEY [#]

SW71 6

1 2

SOFTKEY_RIGHT

SW71 8

1 2

POWERKEY

END

SW7 02

1 2

KEY [7]

SW7 07

1 2

KEY [8]

SW7 12

1 2

KEY [9]

SW7 17

1 2

KEY [SEND]

SW70 3

1 2

KEY [4]

SW70 8

1 2

KEY [5]

SW71 3

1 2

KEY [6]

SW7 04

1 2

KEY [1]

SW7 09

KEY [2]

SW7 14

1 2

KEY [3]

SOFTKEY_LEFT

SW7 05

1 2

KEY_[UP]

SW7 10

1 2

KEY_[DOWN]

SW7 15

1 2

KEYROW_0 [2]

KEYROW_1 [2]

KEYROW_2 [2]

KEYROW_3 [2]

POWER_KEY [4]

Figure 1.7. Keypad Connections

As the End Key doubles for the ON / OFF key, it is allocated an entire row of the keyboard scan. Keyboard scanning is controlled by software.

– 1–6 –

1.2.4. Subscriber identity Module (SIM)

The SIM interface is designed to support 3 V SIM card. And work voltage is supplied by ADP3408 "VSIM" (2.85 V).

0x00 SMSMR SIM Character Mode Register Read/Write 0x02 SMBRR SIM Bit Rate Register Read/Write 0x04 SMSCR SIM Control Register Read/Write 0x06 SMTDR SIM Data Transmit Register Read/Write 0x0A SMRDR SIM Data Receive Register Read/Write 0x08 SMSSR SIM Status register Read/Write 0x0C SMSCMR SIM Smart Card Mode Register Read/Write

1.2.5. CPU Memory

To reduce component space, the phone uses a BGA package with Dual operation Flash memory and SRAM MCP. The following memory configuration is used: 32-Mbit Flash memory organized as 2M * 16bits or 4M * 8-bit 4-Mbit SRAM organized as 2M * 16-bit

1.2.6. LCD

The LCD module consists of a LCD glass, white LED and driver chip connection to the Main PCB via a flexible PCB strip. Resolution: 112x64 pixels. It can accommodate Chinese and large character sets. The LCD driver is controlled by setting the command register through the AD6522 u-wire interface and an I/O line that distinguishes between command or data. To send data or a command to the display driver, the nDISPLAYCS line is used for chip select. LCD_CTL is set high to send data and set low to send commands.

1.2.7. Real Time Clock (RTC)

Clock functions are provided by a Real Time Clock built into AD6522. The module is synchronized by a

32.768 kHz crystal and has a backup power source provided by a capacitor. AD6522 has a clock auto compensation function to take into account any inaccuracies of the crystal. This is able to calibrate out crystal tolerance / drift by writing to the compensation registers. This functionality allows the application software to implement standard, calendar, or organizer functions such as:

Time and date display Programmable alarm

Programmable mobile activation The RTC interrupt is routed through the IRQ-controller to the MCU or the DSP, as defined by software in interrupt configuration registers.

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