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LGE Internal Use Only
Copyright © 2008 LG Electronics. Inc. All right reserved.
Only for training and service purposes
3. TECHNICAL BRIEF
3.3.4 Voice Call
A. Voice call Downlink Mode(Receiver, Speaker, Headset)
Figure 3-3-4. Voice call Downlink Scheme
This section provides a detailed description of the Voice Call RX functions.
The voice decoder accepts a serial input stream of either I2S or linear PCM coded speech or voice
data. The signals are then passed through the digital PGAs and the receive band-pass filter(the
next step in the CODEC receive path). Thereafter, the signals pass the digital to analog converters
(DACs) and then the signal is fed to the analog RX-PGAs, which precedes the output amplifiers
(BEARP/N, SPKRP/N, AUXO1/2). The analog RX-PGAs and analog output amplifiers can be
individually completely powered down. The DAC, RX filter, digital RX-PGA and digital PCM/I2S
interface are powered down in common, using a signal I2C bit.
• Receiver Mode : BEARP/N Port
Æ
Receiver(8
Ω
)
• Loud Speaker Mode : SPK Amp
Æ
SPKRP/N
Æ
AUDIO AMP(MAX9877)
Æ
Speaker(8
Ω
)
• Headset Mode : Auxiliary audio amplifier
Æ
AUXO1/2
Æ
AUDIO AMP(MAX9877)
Æ
Head Phone