LG -A120 Service Manual page 16

Radio
MT6223D integrates a mixed-signal Baseband front-end in order to provide a well-organized
radio interface with flexibility for efficient customization. It contains gain and offset calibration
mechanisms, and filters with programmable coefficients for comprehensive compatibility control on
RF modules. This approach also allows the usage of a high resolution D/A Converter for controlling
VCXO or crystal, thus reducing the need for expensive TCVCXO. MT6223D achieve great
MODEM performance by utilizing 14-bit high resolution A/D Converter in the RF downlink
path. Furthermore, to reduce the need for extra external current-driving component, the driving
strength of some BPI outputs is designed to be configurable.
Debug Function
The JTAG interface enables in-circuit debugging of software program with the ARM7EJ-S core.
With this standardized debugging interface, MT6223D provides developers with a wide set of
options in choosing ARM development kits from different third party vendors. Low Power Features
MT6223D offers various low-power features to help reduce system power consumption. These
features include Pause Mode of 32KHz clocking at Standby State, Power Down Mode for individual
peripherals, and Processor Sleep Mode. In addition, MT6223D are also fabricated in advanced low
leakage CMOS process, hence providing an overall ultra low leakage solution.
Power Management
MT6223D integrates all regulators that a voice-centric phone needs. Seven LDOs optimized for
Specific GSM/GPRS baseband sub-systems are included, and a RF transceiver needed LDO is
also built-in. Besides Li-Ion battery charge function, SIM card level shifter interface, two open-drain
output switches to control the LED and vibrator are equipped. Other power management schemes
such as thermal overload protection, Under Voltage Lock-out Protection (UVLO), over voltage
protection and oower-on reset and start-up timer are also MT6223D features. Besides, 3 NMOS
switches controlling the RGB LEDs are also embedded to reduce BOM coount.
Package
The MT6223D device is offered in 9mm×9mm, 224-ball,
0.5 mm pitch, TFBGA package.
3.1.2 Platform Feature
General
Integrated voice-band, audio-band and base-band analog front ends
TFBGA 9mm×9mm, 224-ball, 0.5 mm pitch package
MCU Subsystem
ARM7EJ-S 32-bit RISC processor
High performance multi-layer AMBA bus
Java hardware acceleration for fast Java-based games and applets
Operating frequency: 26/52 MHz
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