LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3.10 Audio Interface
The audio front-end of E-GOLDvoice offers the digital and analog circuit blocks for both receive and
transmit audio operation and ringing. It features a high-quality, digital-to-analog path with amplifying
stages for connecting acoustic transducers to the E-GOLDvoice. In the transmit direction the supply
voltage generation for microphones, low-noise amplifier and analog to digital conversion are integrated
on the E-GOLDvoice.
For E-GOLDvoice the EPp1/EPn1 driver are used as differntial Earpiece-Driver, EPPa1 is used as
single-ended Headset-Driver.
The audio front-end itself can be considered to be organized in three sub-blocks:
• Interface to processor cores (TEAKlite and - indirectly - C166S)
• Digital filters
• Analog part.
3. TECHNICAL BRIEF
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Figure 3-10-1 Audio interface
P12
VMIC
LOUD2
K14
R13
MICN1
R12
MICN2
MICP1
P15
MICP2
P11
EPP1
M12
EPPA1
M14
L15
LOUD1
EPN1
N15
1000p
C127
VMIC
HS_MIC_P
SPK_P
SPK_N
MIC_N
MIC_P
REC_P
REC_N
HS_REC
HS_MIC_N