Read Panasonic KX-NT551RU-B Service Manual online
9
KX-NT551RU/KX-NT551RU-B
4.2.4.
Analog Circuit
1. Speaker phone call
Transmitting signal is input from microphone (differential amplifier circuit)
input to IC502-L19, M19 A/D conversion, Gain
adjustment and echo cancel by a built-in DSP of IC502.
Receiving signal input from IP Line
Receiving signal input from IP Line
Gain adjustment and D/A conversion by DSP of IC502 output from IC502-V18, V19
output to Speaker.
2. Handset call
Transmitting signal is input from handset microphone
input to IC502-K18, K19 A/D conversion, Gain adjustment by a
built-in DSP of IC502.
Receiving signal input from IP Line
Receiving signal input from IP Line
Gain adjustment and D/A conversion by DSP of IC502 IC502-V18, V19 output from
output to handset speaker.
IC502
SPP
SPM
DGND
DGND
DGND
DGND
C128
C114
C115
D103
D104
CL-SPP
CL-SPM
R122
R134
C108
DGND
DGND
C121
C110
DGND
C111
DGND
L102
NC
L103
C124
L109
L107
C129
R104
R109
C117
R106
C116
C119
C120
R105
R110
C109
R107
AGND
AGND
AGND
AGND
MICP
MICM
R102
R103 0
R123
AGND
MICBIAS
C149
C112
C113
C105
C106
D101
D102
CL-MICP
CL-MICM
AGND
AGND AGND
AGND
AGND
V19
V18
L19
M19
Speaker
Mic
IC502
Handset
R116
C101
C103
C145
R114
C142
R112
C127
C138
R119
C141
R120
3.3k
C139
R115
AGND
AGND
AGND
AGND
AGND
AGND
AGND
AGND
R108
R111
AGND
MICBIAS
R131
C150
C125
C126
C133
C134
C102
C118
C122
D106
D107
D108
D109
JK102
2
3
4
5
L104
L105
AGND
AGND
AGND
AGND
AGND
M18
M17
K18
K19
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