LGC-340/345W
27
LGIC
LG Information & Communications, Ltd.
2.3 Circuit Description
[Figure 2-1] Block Diagram of Digital/Voice Processing Part
2.3.1 Keypad/LCD and Receptacle Part
Once the keypad is pressed, the key signals are sent out to MSM3000(U16) for processing. In addition, when the
key is pressed, the keypad lights up through the use of 16 LEDs. The status and operation of a mobile station are
displayed on the screen for the user with the characters and icons on the LCD.
Receptacle(CON3) exchanges audio signals and data with external sources and then, receives power from the
battery or external batteries.
2.3.2 Audio Processing Part
MIC signals are inputted into the audio codec, and amplified with programmable gain(2dB step), and converted
into digital signals(PCM). Then, they are inputted into MSM3000.
In addition, digital audio signals(PCM) outputted from MSM3000 are converted into analog signals after going
through the audio codec. These signals are amplified with programmable gain on codec’s internal AMP and
transferred to the ear piece. Then, the signals of ringer activate the ringer is generated in MSM3000 and drive the
ringer circuit(Q10, Q11).
AT53BV164
Digital Part
MSM 3000
memory
Flash ROM
EEPROM
CODEC
Key Pad
Receptacle
LCD
MIC
Buzzer
EarPiece
Power
3.0 v
3.0 v