LG KE820 Service Manual page 49

3. TECHNICAL BRIEF
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 8Ω load, 25mW per channel of continuous average power
into stereo 32Ω 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.
AMP_IN_R
AMP_IN_L
SDA
SCL
2V72_IO
C239 220n R436 0
C245 220n R437 0
R229 100K
C247
0.1u
Figure 22 Audio amplifier Sub-system IC
3V3_AUDIO
SPK_N
SPK_RCV_N
SPK_RCV_SEL
RCV_N
C242 C240 C244
100p 100p 0.1u
3V3_AUDIO
FM_SND_R
AMP_IN_R
FM_BBP_SEL
BBP_SND_R
C251
0.1u
Figure 23 Audio signal distribute analog switch
3V3_AUDIO
C238
C236 C237
0.1u 1u
4.7u
B4 D1
PHONE_IN MONO+
D4 B1
RIN MONO-
E4 D5
LIN U210 ROUT
LM4845
B5
NC1
A2 D2
I2CSPIVDD NC2
A1 E5
SDA LOUT
B2
SCL
B3
ID_ENB
E1 E2
I2CSPI_SEL CBYPASS
C248
470n
U208 NLAS5223BMNR2G
1 10
SPK_P
VCC NO2
2 9
SPK_RCV_P
NO1 COM2
3 8
COM1 IN2
4 7
RCV_P
IN1 NC2
5 6
NC1 GND
C243 C241
100p 100p
U211 NLAS5223BMNR2G
1 10
FM_SND_L
VCC NO2
2 9
AMP_IN_L
NO1 COM2
3 8
COM1 IN2
4 7
BBP_SND_L
IN1 NC2
5 6
NC1 GND
- 50 -
SPK_P
SPK_N
HS_OUT_R
HS_OUT_L
C447
0.22u