Panasonic KX-DT346UA Service Manual ▷ View online
13
KX-DT346UA/KX-DT346UA-B
4.2.8.
Analog Circuit
This circuit performs the setting of the call path/vol. adjustment in each call mode by DSP built in IC2.
The audio gain of each call is determined by download data from PBX.
The audio gain of each call is determined by download data from PBX.
• IC2 sends each audio data to IC6 by PCM interface.
• IC2 receives each audio data from IC6 by PCM interface.
• IC2 receives each audio data from IC6 by PCM interface.
1. Handset Call
Transmitting signal is inputted from handset microphone and amplified by IC6 built-in Amp
→ A/D conversion→inputted to IC2
in PCM data
→Gain adjustment by DSP of IC2→then sent to PBX.
Transmitting signal inputted from handset microphone is controlled by transmission switching SW IC8 as below.
IC1-pin 52 L : Handset Call
(IC1-pin 52 H : Headset Call)
Receiving signal inputted from PBX is
IC1-pin 52 L : Handset Call
(IC1-pin 52 H : Headset Call)
Receiving signal inputted from PBX is
→Gain adjustment by DSP of IC2→D/A conversion after the input to IC6 in PCM
data
→IC6 built-in Amp output→outputted from IC2 built-in Amp to handset.
2. Headset Call
Transmitting signal is inputted from headset microphone and amplified by IC6 built-in Amp
→ A/D conversion→inputted to IC2
in PCM data
→Gain adjustment by DSP of IC2→then sent to PBX.
Transmitting signal inputted from headset microphone is controlled by transmission switching SW IC8 as below.
IC1-pin 12 H : Headset Call
(IC1-pin 12 L : Handset Call)
Receiving signal inputted from PBX is
IC1-pin 12 H : Headset Call
(IC1-pin 12 L : Handset Call)
Receiving signal inputted from PBX is
→Gain adjustment by DSP of IC2→D/A conversion after the input to IC6 in PCM
data
→IC6 built-in Amp output→outputted from Q6 (transistor for buffer) to headset.
3. Speakerphone Call
Speakerphone call realizes all double-call by DSP(echo canceller) built in IC2. For a call in the most appropriate condition,
DSP checks voice level of the calling party, acousticity in a room, voice level of the other party and state of the line of contact,
and cancels echo in transmitting and receiving at the start of calling. It operates in a half double-call state in a few seconds for
the check.
DSP checks voice level of the calling party, acousticity in a room, voice level of the other party and state of the line of contact,
and cancels echo in transmitting and receiving at the start of calling. It operates in a half double-call state in a few seconds for
the check.
Transmitting signal is inputted from SP phone mic. and amplified by IC6 built-in Amp
→ A/D conversion→inputted to IC2 in
PCM data
→Gain adjustment by DSP of IC2, then sent to PBX through echo canceller.
Receiving signal inputted from PBX is
→Gain adjustment by DSP through echo canceller of IC2 →inputted to IC6 in PCM
data
→D/A conversion→IC6 built-in Amp output→outputted from IC7(Amp) to speaker.
Power Amp IC7 is controlled as follows;
IC1-pin 13 L
IC1-pin 13 L
→IC7-ON
IC1-pin 13 H
→IC7-OFF
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KX-DT346UA/KX-DT346UA-B
IC2
H
A
ND
S
E
T
T
X
P
C
M T
X
DATA
HAND
SET
RX
P
C
M
TX DATA
H
E
A
D
S
E
T TX
HEAD
SET
RX
SP-P
H
O
N
E
T
X
SP-P
H
O
N
E
RX
15
KX-DT346UA/KX-DT346UA-B
4.2.9.
Bluetooth I/F Circuit
The telephone call by the Bluetooth Headset become possible by connecting the Bluetooth unit(KX-NT307).
This circuit performs the setting of the call path/vol. adjustment in each call mode by DSP built in IC2.
The audio gain of each call is determined by internal data from CPU(IC1).
This circuit performs the setting of the call path/vol. adjustment in each call mode by DSP built in IC2.
The audio gain of each call is determined by internal data from CPU(IC1).
16
KX-DT346UA/KX-DT346UA-B
5 Location of Controls and Components
5.1.
Name and Locations
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