Panasonic KX-TCD420RUM / KX-TCD420RUS / KX-A142RUM / KX-A142RUS Service Manual ▷ View online
18 FREQUENCY TABLE (MHz)
BASE UNIT
HANDSET
Channel No
Transmit Frequency
Receive Frequency
Transmit Frequency
Receive Frequency
1
1897.344
1897.344
1897.344
1897.344
2
1895.616
1895.616
1895.616
1895.616
3
1893.888
1893.888
1893.888
1893.888
4
1892.160
1892.160
1892.160
1892.160
5
1890.432
1890.432
1890.432
1890.432
6
1888.704
1888.704
1888.704
1888.704
7
1886.976
1886.976
1886.976
1886.976
8
1885.248
1885.248
1885.248
1885.248
9
1883.520
1883.520
1883.520
1883.520
10
1881.792
1881.792
1881.792
1881.792
Note:
Channel No. 10: In the Test Mode on Base Unit and Handset.
51
KX-TCD410RUM / KX-TCD410RUS / KX-TCD412RUM / KX-TCD412RUS / KX-A141RUM / KX-A141RUS / KX-A142RUM / KX-A142RUS
19 BLOCK DIAGRAM (BASE UNIT)
Audio
A/D
D/A
Analog
Front End
Front End
LED
CPU
BBIC
IC2
HOOK
RXAF
TXAF
DSP
BMC
Speech Encoding
Speech Decoding
RF
Interface
Interface
Burst Building
Burst Decoding
ADPCM
Codec Filter
Codec Filter
EEPROM
IC1
SDA
SCL
SYRI
RSSI
SYEN
RXDA
TXDA
J2
J1
IC3
4.0V
Reg.
Reg.
2.65V
Reg.
Reg.
4.0V
2.65V
VUNREG
40
41
28
24
24
61
9
6
6
30
11
11
63
64
64
6
5
6
4
RF Module
20
30
10
33
CHARGE
CONTACT
CONTACT
18
16
XTAL
X1
10.368
MHz
MHz
DTXAF
DTXAF
27
26
Bell/Caller ID
Interface
Interface
ANT1
ANT2
ANT2
to Tel_Line
A
B
A
B
to AC Adaptor
Limit
Register
Register
Bridge Rect
D2
Hook Switch
Q2, Q3
KX-TCD410RUM/RUS&412RUM/RUS BLOCK DIAGRAM (BASE UNIT)
A0...A18 D0...D7 30
IC4
Flash PROM
DATA
CTRL
ADDRESS
K
X
-T
C
D
41
0R
U
M
/K
X
-T
C
D
41
0R
U
S
/K
X
-T
C
D
41
2R
U
M
/K
X
-T
C
D
41
2R
U
S
/K
X
-A
14
1R
U
M
/K
X
-A
14
1R
U
S
/K
X
-A
14
2R
U
M
/K
X
-A
14
2R
U
S
#
20 CIRCUIT OPERATION (BASE UNIT)
20.1. Outline
Base Unit consists of the following ICs as shown in BLOCK DIAGRAM (BASE UNIT) (P.52).
·
DECT BBIC (Base Band IC): IC2
−
−
Handling all the audio, signal and data processing needed in a DECT base unit
−
−
Controlling the DECT specific physical layer and radio section (Burst Module Controller section)
−
−
ADPCM codec filter for speech encoding and speech decoding (DSP section)
−
−
Echo-cancellation and Echo-suppression (DSP section)
−
−
Any tones (tone, sidetone, ringing tone, etc.) generation (DSP section)
−
−
DTMF receiver (DSP section)
−
−
Clock Generation for RF Module
−
−
ADC, DAC, timer, and power control circuitry
−
−
All interfaces (ex: RF module, EEPROM, LED, Analog Front End, etc.)
·
RF Module: IC3
−
−
PLL Oscillator
−
−
Detector
−
−
Compress/Expander
−
−
First/Second Mixer
−
−
Amplifier for transmission and reception
·
EEPROM: IC1
−
−
Temporary operating parameters (for RF, etc.)
·
Additionally,
−
−
Power Supply Circuit (+4.0V, +2.65V output)
−
−
Crystal Circuit (10.368MHz)
−
−
Charge Circuit
−
−
Telephone Line Interface Circuit
53
KX-TCD410RUM / KX-TCD410RUS / KX-TCD412RUM / KX-TCD412RUS / KX-A141RUM / KX-A141RUS / KX-A142RUM / KX-A142RUS
20.2. Power Supply Circuit
The power is supplied to the DECT BBIC, RF Module, EEPROM, Relay Coil, LED and Charge Contact from AC Adaptor (+6V)
as shown in Fig.101. The power supply is as follows;
as shown in Fig.101. The power supply is as follows;
·
DECT BBIC (IC2): J2(+6V)
→
D4
→
Q9
→
D5
→
Q8
→
IC2
·
RF Module (IC3): J2(+6V)
→
D4
→
Q9
→
L8
→
IC3
·
EEPROM (IC1): J2(+6V)
→
D4
→
Q9
→
D5
→
Q8
→
IC1
·
Flash Memory (IC4): J2(+6V)
→
D4
→
Q9
→
D5
→
Q8
→
IC4
·
LED (LED1): J2(+6V)
→
D4
→
Q9
→
R68
→
LED1
·
Charge Contact (TP84): J2(+6V)
→
D4
→
R43, R44
→
L4
→
TP84
<Fig.101>
54
KX-TCD410RUM / KX-TCD410RUS / KX-TCD412RUM / KX-TCD412RUS / KX-A141RUM / KX-A141RUS / KX-A142RUM / KX-A142RUS
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