Panasonic KX-TGJ310RU / KX-TGJ312RU / KX-TGJ320RU / KX-TGJ322RU / KX-TGJA30RU Service Manual ▷ View online
13
KX-TGJ310/KX-TGJ312/KX-TGJ320/KX-TGJ322/KX-TGJA30
4.3.5.
Telephone Line Interface
Telephone Line Interface Circuit:
Function
Function
• Bell signal detection
• ON/OFF hook and pulse dial circuit
• Side tone circuit
• ON/OFF hook and pulse dial circuit
• Side tone circuit
Bell signal detection and OFF HOOK circuit:
In the idle mode, Q141 is open to cut the DC loop current and decrease the ring load. When ring voltage appears at the Tip (T)
and Ring (R) leads (When the telephone rings), the AC ring voltage is transferred as follows:
T
and Ring (R) leads (When the telephone rings), the AC ring voltage is transferred as follows:
T
→ C105 → R103→ C110→ R111→ C111→Pin12 of IC501 [BELL]
When the CPU (BBIC) detects a ring signal, Q141 turns on, thus providing an off-hook condition (active DC current flow through
the circuit). Following signal flow is the DC current flow.
T
the circuit). Following signal flow is the DC current flow.
T
→ D101 → Q141 → Q161 → R163 → D101 → P101 → R
ON HOOK Circuit:
Q141 turns off. Q141 is disconnected as to cut the DC loop current and to cut the voice signal. The unit is consequently in an
on-hook condition.
on-hook condition.
Pulse Dial Circuit:
Pin 13 of BBIC(IC501) turns Q141 ON/OFF to make the pulse dialing.
Side Tone Circuit:
Basically this circuit prevents the TX signal from feeding back to RX signal. As for this unit, TX signal feed back from Q161 is
canceled by the canceller circuit of BBIC.
canceled by the canceller circuit of BBIC.
L1T
L1R
C110
820p
C109
820p
C113
0.082u
+1.8V
3
7
1
C
u
1
.
0
4
4
1
Q
*
3
D
N
G
Q161
B
C
E
C142
K0.01u
*Q141
B
E
C
C152
0.01u
L2R
L2T
*C143
N
C
R11
7
100
k
C116
100n
R116
5.6M
R115
5.6M
C115
100n
R118
100
k
D132
NC
D133
NC
*C16
7
2
7
00p
*C164
0
.1u
*C162
10u
*C166
NC
P101
*S
A101
2
1
D101
1
4
2
C101
680p
C102
680p
C106
680p
C105
680p
R163
39
*C120
N
C
*C121
N
C
*R120
NC
GAP
1
2
R16
7
NC
*S
A102
NC
2
1
*D143
NC
*C1
7
1
0.039u
*D142
NC
*C161
N
C
C111
0.033u
C103
0.01u
C104
0.01u
*D141
Q142
C184
1u
R102
5.6M
R101
5.6M
R103
180k
R104
180k
R109
82k
R11
08
2
k
R111
3.9k
R11
2
120
k
*R11
9
NC
R141
100k
R142
2.
7k
*R146
1
0
*R144
1
0
k
R145
3.9
k
*R148
680
R151
100k
*R160
270
*R16
2N
C
*R169
3
9
k
4
6
1
R
*
k
2
.
2
R165
2
7k
R166
8.2
k
R168
4.
7k
*R1
7
0
1.5
k
*R14
7
10
K
*C141
R152
130
k
*Q143
NC
R143
NC
*R153
NC
*R154
NC
C181
560p
GND3
(YELLOW)
RX
TX
(BROWN)
(RED)
(BLACK)
NL_CID
3
Pin 26 of IC501
Pin 25 of IC501
Pin 1
1
o
f IC501
Pin 14 o
f IC501
Pin 13 o
f IC501
P
A
RA
DET
PUL
S
E MUTE
HOOK
CALLER ID/BELL
DETECTION
Pin 18 of IC501
Pin 17 of IC501
Pin 17 of IC501
Pin 12 of IC501
Pin 19 o
f IC501
Pin 21 o
f IC501
Pin 22 of IC501
Pin 15 of IC501
4.
7
u
14
KX-TGJ310/KX-TGJ312/KX-TGJ320/KX-TGJ322/KX-TGJA30
4.3.6.
Transmitter/Receiver
• Audio Circuits and DTMF tone signal circuits.
Base Unit and Handset mainly consist of RF Module and DECT BBIC.
Base Unit and Handset transmit/receive voice signal and data signal through the antenna on carrier frequency.
Base Unit and Handset transmit/receive voice signal and data signal through the antenna on carrier frequency.
Signal Path:
*Refer to Signal Route(P.17).
4.3.6.1.
Transmitter Block
The voice signal input from the TEL LINE interface goes to DECT BBIC (IC501) as shown in Block Diagram (Base
Unit_Main)(P.8)
The voice signal passes through the analog part of IC501 where it is amplified and converted to a digital audio stream signal.
The burst switch controller processes this stream performing encryption and scrambling, adding the various other fields to
produce the GAP (Generic Access Profile) standard DECT frame, assigning to a time slot and channel etc.
In IC501, the carrier frequency is changing, and frequency modulated RF signal is generated.In IC501,RF signal is amplified,
and radiated from antenna. Handset detects the voice signal or data signal in the circuit same as the following explanation of
Unit_Main)(P.8)
The voice signal passes through the analog part of IC501 where it is amplified and converted to a digital audio stream signal.
The burst switch controller processes this stream performing encryption and scrambling, adding the various other fields to
produce the GAP (Generic Access Profile) standard DECT frame, assigning to a time slot and channel etc.
In IC501, the carrier frequency is changing, and frequency modulated RF signal is generated.In IC501,RF signal is amplified,
and radiated from antenna. Handset detects the voice signal or data signal in the circuit same as the following explanation of
Receiver Block.
4.3.6.2.
Receiver Block
The signal of 1900 MHz band (1881.792 MHz ~ 1897.344 MHz) which is input from antenna is input to IC501 as shown in Block
Diagram (Base Unit_Main)(P.8).
In IC501, the signal of 1900 MHz band is downconverted to 864 kHz signal and demodulated, as GAP (Generic Access Profile)
standard DECT frames. It passes through the decoding section burst switch controller where it separates out the frame
information and performs de-encryption and de-scrambling as required. It then goes to the DSP section where it is turned back
Diagram (Base Unit_Main)(P.8).
In IC501, the signal of 1900 MHz band is downconverted to 864 kHz signal and demodulated, as GAP (Generic Access Profile)
standard DECT frames. It passes through the decoding section burst switch controller where it separates out the frame
information and performs de-encryption and de-scrambling as required. It then goes to the DSP section where it is turned back
into analog audio. This is amplified by the analog front end, and goes to the TEL LINE Interface.
4.3.6.3.
Pulse Dialling
During pulse dialling the hookswitch (Q141, Q142) is used to generate the pulses using the HOOK control signal, which is set
high during pulses. To force the line impedance low during the “pause” intervals between dial pulses, the PULSE_DIAL signal
high during pulses. To force the line impedance low during the “pause” intervals between dial pulses, the PULSE_DIAL signal
turns on Q144.
15
KX-TGJ310/KX-TGJ312/KX-TGJ320/KX-TGJ322/KX-TGJA30
4.4.
Block Diagram (Handset)
CHARGE(+)
CHARGE(-)
CHARGE CIRCUIT
POWER
SUPPL
Y
CIRCUIT
OPTIONAL
BA
TT(-)
BA
TT(+)
SPEAKER
MIC
RECEIVER
CP3V/CP4V
A
VD/C
VDD
CP_OUT
VBA
T
RF/VDD
VDD/P
A
RF BL
OCK
IC 1
X
TAL1
X
TAL2
LC
D
IC4
PROGRAM
FLASH
KEY P
A
D
KEY BA
CK
LIGHT
1
2
3
4
5
Headset Jack
Q1
+1.8V
+1.8V
CN1
KX
-T
GJA30 BL
OCK DIA
GRAM (HANDSE
T
)
16
KX-TGJ310/KX-TGJ312/KX-TGJ320/KX-TGJ322/KX-TGJA30
4.5.
Circuit Operation (Handset)
4.5.1.
Outline
Handset consists of the following ICs as shown in Block Diagram (Handset) (P.15).
• DECT BBIC (Base Band IC): IC1
- All data signals (forming/analyzing ACK or CMD signal)
- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter,LCD, RF Power Amp.)
- PLL Oscillator
- Detector
- Compress/Expander
- Reception
- Integrated 1.9 GHz PA for DECT
- All interfaces (ex: Key, Detector Circuit, Charge, DC/DC Converter,LCD, RF Power Amp.)
- PLL Oscillator
- Detector
- Compress/Expander
- Reception
- Integrated 1.9 GHz PA for DECT
• QSPI FLASH MEMORY: IC4
- Main Program D/L Area
- Following information data is stored
- Following information data is stored
- Settings
ex: ID code, user setting
ex: ID code, user setting
4.5.2.
Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6 V: BATT+)
BATTERY(2.2 V ~ 2.6 V: BATT+)
→ Q1 (1.8 V), IC1-44pin (CP3V), IC1 45pin(CP4V)
The Reset signal generates IC1 (71 pin) and 1.8 V.
4.5.3.
Charge Circuit
Circuit Operation:
When charging the handset on the Base Unit, the charge current is as follows;
DC+(5.5 V)
→ R371 → R372 → D362 → CHARGE+(Base) → CHARGE+(Handset) →
→ Q3 → BATTERY+... Battery...
BATTERY-
→ R45 → GND → CHARGE-(Handset)→ CHARGE-(Base) → GND → DC-(GND)
In this way, the BBIC on Handset detects the fact that the battery is charged.
The charge current is controlled by switching Q9 of Handset.
The charge current is controlled by switching Q9 of Handset.
Refer to Fig.101 in Power Supply Circuit/Reset Circuit (P.16).
4.5.4.
Battery Low/Power Down Detector
Circuit Operation:
“Battery Low” and “Power Down” are detected by BBIC which check the voltage from battery.
The detected voltage is as follows;
The detected voltage is as follows;
• Battery Low
Battery voltage: V(Batt) 2.25 V ± 50 mV
The BBIC detects this level and "
" starts flashing.
• Power Down
Battery voltage: V(Batt) 2.0 V ± 50 mV
The BBIC detects this level and power down.
4.5.5.
Speakerphone
The hands-free loudspeaker at SP+ and SP- is used to generate the ring alarm.
1.8V
Battery +
Reset
(IC1_71 pin)
(IC1_71 pin)
Q2
R8
R8
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