LG KE970 Service Manual page 46

3.13.1. Audio amplifier sub system IC with 3D effect
Audio amplifier sub system IC is an audio power amplifier capable of delivering 500mW of
continuous average power into a mono 8 load, 25mW per channel of continuous average power
into stereo 32 single-ended (SE) loads. The LM4845 features a 32-step digital volume control and
eight distinct output modes. The digital volume control, 3D enhancement, and output modes
(mono/SE/OCL) are programmed through a two-wire I2C interface that allows flexibility in routing
and mixing audio channels.
2V72_IO
C263
0.1u
CTS_0
RTS_0
HS_OUT_R
HS_OUT_L
Figure 21 Audio signal distribute analog switch
3V3_AUDIO
C255
1u
11
SCL SCL
10
SDA SDA
13 U207
ID_ENB
R233 100K LM4946SQX
2
VOC
7
I2CSPI_VDD
14
I2CSPI_SEL
C267 470n
C270
0.068u R243
C269 1u
4.7K
Figure 20 Audio amplifier Sub-system IC
2V85_IO2
2V72_IO
R224
100
R225
C253 100p
10K
U205
R226 47
1
VCC NO2
2
NO1 COM2
R227 47
3
COM1
4
IN1 NC2
5
NC1 GND
NLAS5223BMNR2G
3V3_AUDIO
R235
100
C261 100p
SPK_N
U208
1
VCC
2
SPK_P NO1
3
COM1
4
IN1
5
RCV_P NC1
NLAS5223BMNR2G
RCV_N
- 47 -
3. TECHNICAL BRIEF
C256
0.1u
23
MONO_IN+
22
MONO_IN-
15
MONO+ SPK_P
17
MONO- SPK_N
19
RHP3D1
C260
0.068u
24
RHP3D2
R237
4.7K
R238 0
8
RIN BBP_SND_R
C262 220n
5
ROUT HS_OUT_R
C264 100u
C266 100u
HS_OUT_L
R241 0
BBP_SND_L
C268 220n
10
C254
27p
9
MULTI_PORT_2
R228 24
8
IN2 HSO_SEL
7
2V85_IO2
R230 47K
6
C258
27p
MULTI_PORT_3
R232 24
10
C265
NO2
100p
9
COM2 SPK_RCV_N
8
IN2 SPK_RCV_SEL
6
NC2
7
GND
C271
100p
SPK_RCV_P