Panasonic KX-TC1045RUB Service Manual ▷ View online
20 BLOCK DIAGRAM (BASE UNIT)
RX DATA
TX DATA
SQL
PLL-RST
PLL-DATA
PLL-CLK
UNLOCK
TX-POWER
RX-POWER
1st
Mixer
Mixer
RX Filter
ANT
RECEIVING FREQUENCY
39.775~40.000MHz
39.775~40.000MHz
1st
Local
Local
Q106
Q302
Q301, Q303
Q751, Q752
IC351
D101
Q101
Q105
TEL JACK
2nd
Mixer
Mixer
IF AMP
DET
1st IF
Filter
Filter
2nd IF
Filter
Filter
DATA
Filter
Filter
DATA
AMP
AMP
PRE-
AMP
AMP
LINE
AMP
AMP
EXPANDER
COMPRESSOR
LIMITTER
PLL
X201
11.150MHz
29.075
~29.300MHz
~29.300MHz
2nd Local 11.150MHz
DC JACK
DC9V
1
2
4
TIP
RING
3
GND
1
2
1
2
+
Ð
~
~
+
BELL-
DETECT
DETECT
8V
REGULATOR
REGULATOR
RESET
POWER
DOWN
DOWN
TR RLY
SIDE TONE
CIRCUIT
CIRCUIT
MIC
AMP
AMP
IC801
IC702
(FLASH MEMORY)
(FLASH MEMORY)
I/O 0~7
RE
CE
CE
WP
WE
WE
ALE
CLE
RX-POWER
TX-POWER
UNLOCK
PLL-CLK
PLL-DATA
PLL-RST
SQL
TX-DATA
LINE IN
RLY
BELL
RESET
POWER-DOWN
TX-DATA
CHARGE-DET.
LINE OUT
RX-D
A
T
A
H/S-IN
H/S-OUT
IC701
(DSP)
(DSP)
5V
REGULATOR
REGULATOR
CHARGE
CONTACT
CONTACT
C
+
Ð
1
2
3
Q312
TX-DATA
Q313
CHARGE
DETECT
DETECT
37
KX-TC1045RUB
21 NEW CIRCUIT
OPERATION (BASE UNIT)
21.1. TRANSMITTER CIRCUIT
The voice signal or the data signal sent to the handset is
applied in the anode of the variable capacitor diode (VARICAP)
D851.
applied in the anode of the variable capacitor diode (VARICAP)
D851.
21.2. TRANSMITTER OUTPPUT AMP
CIRCUIT
The signal passes through the duplexer and it is radiated from
the antenna.
the antenna.
22 NORMAL CIRCUIT
OPERATION (BASE UNIT)
22.1. Telephone Line Interface
Circuit Operation:
l ANSWER
In the idle mode, Q101 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
l ANSWER
In the idle mode, Q101 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
→
PO101
→
L101
→
R121
→
C116
→
Q106
→
IC701 pin
64.
When the CPU (DSP) detects a ring signal, Q101 turns on,
thus providing an off-hook condition (active DC current flow
through the circuit) and the following signal flow is for the voice
signal.
T
When the CPU (DSP) detects a ring signal, Q101 turns on,
thus providing an off-hook condition (active DC current flow
through the circuit) and the following signal flow is for the voice
signal.
T
→
PO101
→
D101
→
Q101
→
Q105
→
R115
→
D106
→
D101
→
R
l ON HOOK
Q101 is open, Q101 is connected as to cut the DC loop current
and to cut the voice signal. The unit is consequently in an on-
hook condition.
Q101 is open, Q101 is connected as to cut the DC loop current
and to cut the voice signal. The unit is consequently in an on-
hook condition.
l SPECIFICATIONS
In the on-hook state (idle), the current flows between the
telephone line and the unit is as follows:
T
In the on-hook state (idle), the current flows between the
telephone line and the unit is as follows:
T
→
PO101
→
L101
→
R121
→
C116
→
R122
→
C115
→
R120
→
L102
→
R.
The DC component is blocked by C115, C116: thereby
providing an on-hook condition.
The AC interface impedance is over 47 k
providing an on-hook condition.
The AC interface impedance is over 47 k
Ω
; thus, satisfying the
telephone company requirements.
38
KX-TC1045RUB
22.2. TELEPHONE MODE
OPERATION
22.2.1. When a ring signal enters from the
Line
1. The ring detection circuit (Transistor Q106) begins to
operate, so Q106 turns on, thus input a low level to the
BELL pin 64 of the IC701 (CPU).
BELL pin 64 of the IC701 (CPU).
2. To show the arrival of ring signal to the handset, Pin 25 of
IC701 (Tx POWER) becomes low and Tx power is turned
on. Then IC 701 outputs the ring data signal from Pin 97 (Tx
data) and it is transmit to the handset.
on. Then IC 701 outputs the ring data signal from Pin 97 (Tx
data) and it is transmit to the handset.
3. Upon receiving the ring data and the handset is switched
from standby to the talk mode, the base unit receives the
modulated data from the handset, which includes the
information that the handset becomes from Stand by to
Talk. This data is then demodulated at the base unit and
passes through a data signal amplifier of IC701, This signal
modulated data from the handset, which includes the
information that the handset becomes from Stand by to
Talk. This data is then demodulated at the base unit and
passes through a data signal amplifier of IC701, This signal
is then input to Pin 59 of IC701, which causes Q101 and
Q102 release the muting and enable the talk mode.
Q102 release the muting and enable the talk mode.
22.2.2. Circuit-making from the handset
1. When the operator of the handset presses the talk button,
data is transmitted to the base unit. This data is then
demodulated by the base unit and passed through data
signal amplifier of IC801 and enters Pin 59 of IC701(CPU).
demodulated by the base unit and passed through data
signal amplifier of IC801 and enters Pin 59 of IC701(CPU).
2. When the codes coincide, Pin 99 of IC701 becomes a
HIGH voltage level. At this time,the transmit condition is
enabled and the transistor Q102 is turned on.
enabled and the transistor Q102 is turned on.
3. Pin 65 of IC701 becomes LOW (LOW level voltage)and the
IN USE LED LED701 is on.
39
KX-TC1045RUB
22.3. TRANSMITTER SIGNAL
CIRCUIT
22.3.1. Circuit Operation:
1. The signal input from the TEL LINE goes through
IC701 pin 38
→
IC701 pin 35
→
C501
→
C828
→
R817 and
it is input to the
signal amplifier of IC801, pin 9.
This amplifier is included in a limiter circuit.Signal goes
through the compressor and
SPLATTER FILTER, it is output in the pin 3 of IC801. Then
it goes out to the modulation circuit.
signal amplifier of IC801, pin 9.
This amplifier is included in a limiter circuit.Signal goes
through the compressor and
SPLATTER FILTER, it is output in the pin 3 of IC801. Then
it goes out to the modulation circuit.
22.4. RECEIVER RF IF CIRCUIT
22.4.1. Circuit Operation:
The signal of 39 MHz band (39.775~40.000MHz) received at
ANT is filtered at DUP801, passes through the filter AMP of 39
MHz band and input to Pin 41 of IC801. RX VCO which
oscillates at T801 and Pins 44 , 45 of IC801 is input to program
control at inside of IC801. 1st local frequency is controlled to
assigned channel by serial data which is output from Pins 21,
22 and 23 of IC701 (DSP), makes loop with Phase Detector
Out and RX VCO, and locks 1st local frequency. The input
signal, Pin 41 of IC801 and 1st local frequency output from RX
VCO are mixed at inside of IC801, then it passes through
CF801, and 1st IF frequency of 10.700 MHz is generated.
ANT is filtered at DUP801, passes through the filter AMP of 39
MHz band and input to Pin 41 of IC801. RX VCO which
oscillates at T801 and Pins 44 , 45 of IC801 is input to program
control at inside of IC801. 1st local frequency is controlled to
assigned channel by serial data which is output from Pins 21,
22 and 23 of IC701 (DSP), makes loop with Phase Detector
Out and RX VCO, and locks 1st local frequency. The input
signal, Pin 41 of IC801 and 1st local frequency output from RX
VCO are mixed at inside of IC801, then it passes through
CF801, and 1st IF frequency of 10.700 MHz is generated.
Further, 11.150 MHz which is oscillated at X801 and Pins 52 ,
53 of IC801 are mixed at inside of IC801 and filtered at CF802,
and 2nd IF 450 Hz is output.
53 of IC801 are mixed at inside of IC801 and filtered at CF802,
and 2nd IF 450 Hz is output.
22.5. RECEIVER SIGNAL CIRCUIT
22.5.1. Circuit Operation:
1. The detected signal passes through R806
→
C815
→
R807
and it is input to the Pre Amplifier inside of IC801; it passes
through the expander and goes out from pin 21 of IC801.
through the expander and goes out from pin 21 of IC801.
2. The signal passes through C822
→
R811 and it is input to
the Receiver Amplifier of IC801, on pin 17.
3. The signal is output from the amplifier on pin 16 of IC801
and it goes through J884, to main PCB.
40
KX-TC1045RUB
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