Panasonic KX-TC1205RUB / KX-TC1205RUW / KX-TC1205RUS / KX-TC1205RUF Service Manual ▷ View online
15 BLOCK DIAGRAM (HANDSET)
RX VCO
L6, C24
DUPLEXER
DPX1
MIX 1/2
RF AMP
Q1, T3
X1
X3
TX LOOP
DC 3.9V
RF IC
IC1
CPU
IC2
RF
-DATA
-CLK
-STB
-DATA
-CLK
-STB
VTX
RF
-DATA
-CLK
-STB
-DATA
-CLK
-STB
RX
DATA
TX
DATA
POWER
CONTROL
Q4
RF AMP
Q5, T5
TX VCO
Q6, T6, DV1
PLL OSC
RF FILTER
CF1, CF2
ANTENNA
LED
Q8, LED 1-4
RESET
Q11
DIODE
BRIDGE
D1
CHARGE
DTC
IC2 PING37
BUZZER
Q7, BZ1
KEY BOARD
EXP
SPEAKER
REC1
MIC
MC1
CHARGE
TERMINAL
DIODE
BRIDGE
Q9
COM
DC 3.9V
CONTROL LINE
AUDIO SIGNAL
Base
RX LOOP
VC1
BATTERY
3.9V
KX-TC1205RUB/W/S/F BLOCK DIAGRAM (HANDSET)
KX-
TC120
5RUB
/
KX-TC
1205R
U
W
/
/
KX-TC
1205R
US
/
KX-
TC120
5RUF
37
16 CIRCUIT OPERATION
16.1. Outline
Base unit consists of the following ICs as shown in BLOCK DIAGRAM.
•
•
CPU:IC2
−
−
Controlling the whole system
−
−
Forming/analyzing all data signals (ACK, CMD signal etc.*)
−
−
All interfaces (ex: LED, KEY, SP, Mic, LCD, Detector Circuit (Charge/ Power Down)
*Refer to EXPLANATION OF CPU DATA COMMUNICATION (P.32).
•
•
RF IC:IC1
−
−
PLL Oscillator
−
−
Detection
−
−
Compress/ Expander
−
−
first/ second mixer
−
−
Amplifier for transmission and reception
•
•
Additionally,
−
−
Power Supply Circuit
−
−
Reset Circuit
−
−
Charge Circuit
−
−
Telephone Line Interface Circuit
Handset consist of the following ICs as shown in BLOCK DIAGRAM.
•
•
CPU: IC2
−
−
All data signals (forming/analyzing ACK or CMD signal*)
−
−
All interfaces (ex; LED, Key, Buzzer, Detector Circuit, Charge, Battery Low)
−
−
RAM for keeping the data (CH Number, ID Code, etc.)
•
•
RF IC:IC1
−
−
PLL Oscillator
−
−
Detector
−
−
Compress/Expander
−
−
first, second mixer
−
−
Amplifier for transmission and reception
*Refer to EXPLANATION OF CPU DATA COMMUNICATION (P.32).
38
KX-TC1205RUB / KX-TC1205R UW / KX-TC1205R US / KX-TC1205RUF
16.2. Power Supply Circuit
The power supply to the CPU (Digital, Analog) and RF IC from AC Adaptor (+12V) is shown in the diagram below.
The base unit power supply is DC12V. The handset´s power is supplied from 3.6V battery (Nickel-Cadmium battery) which is
installed in the handset.
installed in the handset.
Power supply for transmitter is turned on by a press of "Talk" key on the handset. During the stand-by mode, the unit stops
transmitting but receive thhe signal.
transmitting but receive thhe signal.
Also during on-hook condition (the handset is placed on the base unit), backup power for memory of the last dialed number is
supplied through the battery (3.6V nickel-cadmium in the handset). The memory of this unit is not backed up by the curreent
from the telephone line.
supplied through the battery (3.6V nickel-cadmium in the handset). The memory of this unit is not backed up by the curreent
from the telephone line.
The base unit DC power supply is regulated by Q18, the CPU power is regulated by Q19. The Q8, detects AC Adaptor
powerfailure and maintains the unit cecutiry cord;
powerfailure and maintains the unit cecutiry cord;
Fig. 1
39
KX-TC1205RUB / KX-TC1205R UW / KX-TC1205R US / KX-TC1205RUF
16.3. Reset Circuit (Base Unit)
After power supply from AC adaptor, the VREG is input for making reset signal. Refer to the below waveform.
Fig. 2
Fig. 3
40
KX-TC1205RUB / KX-TC1205R UW / KX-TC1205R US / KX-TC1205RUF
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