Panasonic KX-DT321UA Service Manual ▷ View online
13
KX-DT321UA/KX-DT321UA-B
4.2.8.
Analogue Circuit
This circuit performs the setting of call paths and volume adjustment in each mode of operation, via IC4.
Audio gain settings are downloaded serially from IC6, which obtains its information from the PBX.
Audio gain settings are downloaded serially from IC6, which obtains its information from the PBX.
• IC4 sends PCM audio data (Rx) to IC3 (Digital speakerphone chip) via a PCM interface.
• IC4 receives PCM audio data (Tx) from IC3 via a PCM interface.
• DTMF-like tone (from key-press, etc) is input to IC4 in analogue form.
• IC4 receives PCM audio data (Tx) from IC3 via a PCM interface.
• DTMF-like tone (from key-press, etc) is input to IC4 in analogue form.
1. Handset call:
Transmit signal is input from handset microphone. Pin 57 of IC6 drives analogue switch (IC9) to connect handset microphone
to the signal path. The signal is amplified by an internal amplifier within IC4
to the signal path. The signal is amplified by an internal amplifier within IC4
→ A/D conversion within IC4 → Gain adjustment
(within IC4)
→ sent to PBX via IC3 and IC2 as PCM data.
Receive signal arrives from PBX
→ IC2 → IC3 → D/A conversion from PCM data by IC4→ Gain adjustment by DSP of IC4 →
amplified by 1st amp of IC11
→ output from L52 to the earpiece of the handset.
2. Speakerphone call:
When in speakerphone mode, only a one-way communication path is provided at any given time. IC3 compares the transmit
and receive PCM signals during speakerphone mode, and then provides a one-way communication path, dependant on which
end has the greatest audio content.
Transmit signal is input from the Speaker-phone microphone into IC4. The signal is amplified by an internal amplifier within
IC4
and receive PCM signals during speakerphone mode, and then provides a one-way communication path, dependant on which
end has the greatest audio content.
Transmit signal is input from the Speaker-phone microphone into IC4. The signal is amplified by an internal amplifier within
IC4
→ Gain adjustment within IC4→ sent to PBX via IC3 and IC2 as PCM data.
Receive signal arrives from PBX
→ IC2 → Gain adjustment by IC3 → D/A conversion from PCM data by IC4 → pin 24 of IC4
→ pin 27 of IC4 → pin 28 of IC4 → pin29 of IC4 → output from pin 3 and 4 of IC4 to directly drive the speaker.
3. Headset call:
Transmit signal is input from headset microphone. Pin 57 of IC6 drives analogue switch (IC9) to connect headset microphone
to the signal path. The signal is amplified by an internal amplifier within IC4
to the signal path. The signal is amplified by an internal amplifier within IC4
→ A/D conversion within IC4 → Gain adjustment
(within IC4)
→ sent to PBX via IC3 and IC2 as PCM data.
Receive signal arrives from PBX
→ IC2 → IC3 → D/A conversion from PCM data by IC4→ Gain adjustment by DSP of IC4 →
amplified by 2nd amp of IC11
→ output from L54 to headset.
Speech is prevented from being received by handset by IC6 pin 58 output, which drives base of Q51 (ON) which applies mute
to the handset receive path (when handset is on-hook during call using the headset).
to the handset receive path (when handset is on-hook during call using the headset).
14
KX-DT321UA/KX-DT321UA-B
HANDSET RX
SP PHONE RX
PCM RX DATA
HEADSET RX
PCM TX DATA
HANDSET TX
SP PHONE TX
HEADSET TX
Vref
C C
D E T
SCLK
SCLK
DATA
DATA
CSN
SP_CSN
C513
C511
C508
C507
L52
C510
C515
C514
AG
C405
AG
IC5
1
A0
2
A1
3
A2
4
GND
5
SDA
6
SCL
7
WP
8
VCC
DG
DG
Q52
E
C
B
C521
AG
C501
NC
Q51
E
C
B
AG
C527
C541
NC
AG
AG
AG
L53
AG
C539
C621
AG
C537
C504
C535
C609
NC
IC4
1
PLLCAP
2
AVSS
3
SPON
4
SPOP
5
DVDD
6
DVSS
7
FS
8
DX
9
BCLK
10
DR
11
DATA
12
SCLK
13
CSN
14
TEST
15
AVDD
16
MIC2
17
MIC1
18
MIC3
19
HANDT3
20
HANDT1
21
HANDT2
22
VREF
23
RAGND
24
DAOUT
25
HANDI
26
HANDR
27
RAI
28
RAO
29
SPI
30
TONE
IC2
20
OSR
21
OSX
22
OEP0
25
OCK
1
VDD1
24
VDD24
56
VDD56
7
GND7
17
GND17
46
GND46
49
GND49
2
CSN
48
OSO
47
OSI
44
VDD44
23
GND23
26
OSYNC
19
OEP1/PN9/CK512
K
IC9
1
COM
2
INH
3
GND3
4
GND4
5
A
6
Y1
7
Y0
8
VCC
AG
IC3
1
BCLK
2F
S
3
RIN
4T
IN
5
ROUT
6
TOUT
7
VDD
8
VSS
9
RXON
10
TXON
11
DATA
12
TEST2
13
SCLK
14
CSN
15
TEST1
16
RST
AG
AG
AG
DG
DG
DG
DG
DG
DG
DG
DG
DG
AG
AG
DG
CN6
NC
11
22
Q601
E
C
B
MIC3
SPP
AG2
SPN
MIC1
SP1
SP2
MIC2
JK3
HANDSET JACK
1
2
3
4
JK4
HEADSET JACK
1
2
3
4
5
C608
NC
PN9
RA1
1
2
3
4
5
6
7
8
AG
AG
C525
L51
L54
C400
C401
C402
C403
C503
C517
C534
C536
C516
C518
C520
C519
C540
AG
IC22
NC
1
2
3
4
5
6
7
8
C529
NC
C530
NC
AG
C531
NC
HD/HD_AG
HD_MIC
HD_SP
HS_MIC
HS_SP
AG
C502
C506
C538
DG
C523
AG1
C522
CN3
1
2
3
CN3
4
5
CN4
5
4
3
CN4
2
1
IC11
1
VOUT1
2
VIN1
3
Bypass
4
GND
5
SHUTDOWN
6
VIN2
7
VOUT2
8
VDD
CN1
1
2
CN2
1
2
RA4
1
2
3
4
5
6
7
8
6
7
8
AG
DG
AG
DG
AG
DG
D3.3V
C545
NC
C546
NC
C547
NC
C548
NC
C549
NC
C551
NC
C550
NC
D5V
DG
DG
C526
C552
C553
C532
C500
C533
C556
AG
C554
C555
C557
NC
AG
DG
C542
C528
C543
C544
C404
C558
NC
C559
NC
C512
C509
X1
16.384MHz
R522
R517
R506
R524
R604
R518
R605
R400
R516
R402
R514
R606
R533
NC
R504
R534
0
R510
R500
R502
R521
R520
R526
R529
R509
R530
NC
R401
R523
R513
0
R607
R511
R527
R525
R507
R406
R532
NC
R501
R512
R503
R528
R531
NC
SP
MIC
IC3
IC4
DG/AG
Analog Circuit
15
KX-DT321UA/KX-DT321UA-B
5 Location of Controls and Components
5.1.
Name and Locations
16
KX-DT321UA/KX-DT321UA-B
6 Installation Instructions
Note:
In the illustration below, the telephone line cords are routed for wall mounting. When using the stand, refer to "Attaching the Stand"
and "Cabling" on page 11 for telephone line cabling.
and "Cabling" on page 11 for telephone line cabling.
• Consult your dealer for more details about Digital XDP.
CAUTION:
When connecting a headset
• Ensure that the headset cord is wound around the hook to prevent damage to the connector.
When connecting cords
• Ensure the cords are inserted in the grooves, and are clamped to prevent damage to the connectors.
• When mounting the unit on the wall, cords may be routed upwards or downwards by using the appropriate cord clamp located on
• When mounting the unit on the wall, cords may be routed upwards or downwards by using the appropriate cord clamp located on
the back of the unit.
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