3. TECHNICAL BRIEF
3.15.1 Audio amplifier
We use MAX9877 Audio AMP, which have speaker & headphone amplifiers. An audio signal path can
be selected by I2C command.
AUDIO AMP SUB SYSTEM & SIGNAL DISTRIBUTOR
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| C304 | 1u | |
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| A4 | C1N |
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| C305 |
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| C308 | 1u |
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BB_SND_R |
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C309 | 1u |
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BB_SND_L |
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C311 | 1u |
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FM_SND_R |
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C312 | 1u |
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FM_SND_L |
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| B2 | INB1 |
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| BIAS | |
i2C_SDA |
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| B3 | SDA |
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I2C_SCL |
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| D4 | SCL |
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| RXIN+ | |
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| B4 | |
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VBAT
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C301 | C302 |
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1u | 1u |
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A3 |
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| C5 |
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VSS |
| VDD |
| PVDD |
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| HPR | A1 | R313 | 0 | HSO_R | |
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| HPL | A2 | R314 | 0 | HSO_L | |
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U303 |
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MAX9877AEWP_TG45 | D5 |
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| OUT+ |
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| SPK_P | |
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| B5 |
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| OUT- |
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| SPK_N | |
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| GND | PGND |
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D3 |
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Figure 17. Audio AMP Circuit Diagram
3.15.2 Microphone circuit
C320
MIC_N
22n
C318
MIC_P
22n
MIC | |
C321 |
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39p |
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| L304 |
C319 | 100nH |
39p |
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| L303 |
| 100nH |
C317 |
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39p | EVLC14S02050 |
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MICBIAS
L302 | 100nH |
MIC300
1 | P |
2 | G1 |
3 | |
4 | G2 |
| O |
VA300 C322 10u
Figure 18. Microphone Circuit Diagram
LGE Internal Use Only | - 48 - | Copyright © 2008 LG Electronics. Inc. All right reserved. |
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| Only for training and service purposes |
