Audio Signal Processing & Interface - LG U8130 Service Manual

3. TECHNICAL BRIEF
3.4.2 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 transmit it to DBB Chip (Marita).
This transmitted signal is reformed to fit in GSM & WCDMA Frame format and delivered to RF Chip.
The downlink path amplifies the signal from DBB chip (Marita) and outputs it to Receiver (or Speaker).
The audio interface consists of PCM encoding and decoding circuitry, microphone amplifiers and
earphone drivers.
The PCM encoder and decoder blocks are two-channel, 16-bit circuits with programmable gain
amplifiers (PGA).
The decoder has a receive volume control. The audio inputs and outputs can be switched to normal or
auxiliary ports.
Figure. Audio Interface Detailed Diagram (VICENNE)
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