Analog Baseband; General Description; Audio Signal Processing & Interface - LG T5100 Service Manual

2. TECHNICAL BRIEF

2.8 Analog Baseband

A. General Description
IOTA is Analog Baseband (ABB)Chip supports GSM900, DCS1800, PCS1900, GPRS Class 10 with
Digital Basband Chip(Calypso G2).
IOTA processes GSM modulation/demodulation and power management operations.
Block Description
- Audio Signal Processing & Interface
- Baseband in-phase(I), quadrature(Q) Signal Processing
- RF interface with DBB (time serial port)
- Supply voltage regulation
- Battery charging control
- Switch ON/OFF
- 1.8V/3V SIM card Interface
- 4 internal & 4external ADC channels
B. 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. This transmitted signal is reformed to fit in GSM Frame format and
delivered to RF
Chip. MICBIAS is 2.0Vlevel.
The downlink path amplifies the signal from DBB chip and outputs it to Receiver(or Speaker).
Figure 13. Audio Interface Block Diagram
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