GB310 Service Manual
1
PANTECH
Section 4. Theory of Operation
4.1 Logic Section
4.1.1 DC Distribution and Regulation Part
Applying battery voltage and pressing “END” key on the key pad short-circuits “Ground” and “
PowerON”. AD6535(U102) control that power manage regarding power on/off in handset
Pressing POWERKEY on the key pad is active on the handset.
This will turn on all the LDOs, when PowerON is held low. The power of RF Tx power amplifier is
supplied directly by the battery.
4.1.2 Logic part
4.1.2.1 Summary
The logic part consists of AD6525 ARM7 microprocessor-combined DBB(Digital BaseBand)
GSM-ASIC, COMBO(flash ROM & SRAM), AD6535 ABB(Analog BaseBand) Chip. AD6525 is
GSM-ASIC chipset implemented for GSM terminal’s system control and baseband digital signal
processing.
Major parts used in the logic part are as follows:
1) AD6525 : U101, [ARM7 Processor Core + DBB GSM Signal Processing] ASIC
2) AD6535 : U102, Analog Baseband Processor (Power mana Voice Codec)
3) COMBO MEMORY(Flash ROM : U103, 64Mbit Flash Memory + 16Mbit SRAM )
4.1.2.2 Baseband Digital Signal Processing
AD6525 is a GSM core device containing ARM7 CPU core. AD6525 is 160 pin LFBGA (mini-BGA)
package, consisting of terminal chips. The function and characteristics of clock are as follows:
1) Complete single chip GSM Processor
2) Channel codec sub-system
•
Channel coder and decoder
•
Interleaver and Deinterleaver
•
Encryption and Decryption
3) Control Processor Subsystem including
•
Parallel and serial Display interface
• Keypad
Interface
• SIM
Interface
•
Control of RADIO subsystem
•
Real Time Clock with Alarm
