Microphone - LG C1100 Service Manual

3. TECHNICAL BRIEF

3.10 Microphone

The microphone is placed to the front cover and contacted to main PCB. The audio signal is
passed to AIN1P and AIN1N pins of AD6537B. The voltage supply VMIC is output from
AD6537B, and is a bias voltage for the AIN1P. The AIN1P and AIN1N signals are then A/D
converted by the Voiceband ADC part of AD6537B. The digitized speech is then passed to the
DSP section of AD6525 for processing (coding, interleaving etc.).
AD6537B
AIN1P
AIN1N
100
39p
39p
100
39p
Figure 3-25. MICROPHONE
- 36 -
VMIC
1k
2.2k
39p
10u
39p
0.1u
39p
2.2k
Main Mic
39p