LG KE820 - Multi Port Switch

3. TECHNICAL BRIEF
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3.13.2. Microphone with gain switching circuit
As controlling the MIC_GAIN_SEL, Microphone sensitivity can be selected both -42dB
(MIC_GAIN_SEL set low) and -30dB(MIC_GAIN_SEL set high)
3.14. Multi port switch
Multi port switch has employed to decrease MMI(Multi Media Interface) connector’s pin number. USB,
USART, Remote controlled Headset is connected via this multi port switch. When USB VBUS voltage
is detected Multi port 0 and 1 is connected to USB_DP and USB_DM each. If the remote controlled
headset is plugged into MMI connector, then multi port 0 and 1 in go through REMOTE_INT and
REMOTE_ADC.
Table 8 Multi port switch truth table
Figure 24 Microphone with Gain switching circuit
R122 0
MIC100
SP0102BE3
2
G1
G2
3
G3
5
OUT
1
4
PWR
VA102VA100
C127
10u
L105
100nH
100p
C117
27p
C114
C125
0.1u
VA101
0R120
100p
C128
100nH
L104
C116
0.1u
C126
C115
100p
27p
VMICN
MIC1_P
MIC1_N
VMICP
VBUS_USB='L' VBUS_USB='L' VBUS_USB='H'
JACK_DETECT='L' JACK_DETECT='H'
Pin6 REMOTE_INT TXD USB_DP
Pin7 REMOTE_ADC RXD USB_DM