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LGE Internal Use Only
Copyright © 2009 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. Technical Brief
BL20
23/53
QSC6270
TFT LCD
2.4’ (240 x 320)
D0~D15
CS
WR
RD
RS
RESET
VSYNC_O
+2.8V_VCC
+1.8V_IOVCC
GND
LED ANODE
LED CATHODE 1 to 5
AAT3169
3.8.5 Audio Signal Processing & Interface
Audio signal processing is divided uplink path and downlink path. The uplink path amplifies the audio signal from
MIC and converts this analog signal to digital signal and then transmits it to DBB Chip (MSM6280). This transmitted
signal is reformed to fit in GSM & WCDMA frame format and delivered to RF Chipset. The downlink path amplifies the
signal from DBB chip (MSM6280) and outputs it to receiver (or speaker).
The receive path can be directed to either one of two earphone amplifiers or the auxiliary output. The outputs
earphone1 (EAR1OP, EAR1ON) and auxiliary out (LINE_OP, LINE_ON) are differential outputs. Earphone2 (HPH_L,
HPH_R) is a single-ended output stage designed to drive a headset speaker. The microphone interface consists of two
differential microphone inputs, one differential auxiliary input and a two-stage audio amplifier.