Panasonic KX-TCD410RUT / KX-A141RUT / KX-TCD412RUT / KX-A142RUT Service Manual ▷ View online
22 CIRCUIT OPERATION (HANDSET)
22.1. Outline
Handset consists of the following ICs as shown in BLOCK DIAGRAM (HANDSET) (P.56).
·
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, EEPROM, LCD)
·
RF Module: IC3
−
−
−
−
PLL Oscillator
−
−
−
−
Detector
−
−
−
−
Compress/Expander
−
−
−
−
Amplifier for transmission and reception
22.2. Power Supply Circuit/Reset Circuit
Circuit Operation:
When power on the Handset, the voltage is as follows;
BATTERY(2.2 V ~ 2.6V: TP3)
→
TP14(4V)
→
IC3(6, 27), D3
→
IC1(37)
→
IC1(39, 63) (2.65V)
The Reset signal generates R19, C23 and 2.65V.
22.3. Charge Circuit
Circuit Operation:
·
When charging the handset on the Base Unit, the charge current is as follows;
DC+(5.5V ~ 6V)
→
D4
→
R43, R44
→
CHARGE+(Base)
→
CHARGE+(Handset)
→
L4
→
Q2
→
F1
→
BATTERY+ ... Battery
... BATTERY-
→
R21
→
GND
→
L5
→
CHARGE-(Handset)
→
CHARGE-(Base)
→
GND
→
DC-(GND)
·
When charging the handset on the Charger Unit, the charge current is as follows;
DC+(5.5V ~ 6V)
→
D1
→
R1, R2
→
CHARGE+(Charger Unit)
→
CHARGE+(Handset)
→
F1
→
BATTERY+ ... Battery ...
BATTERY-
→
R21
→
GND
→
CHARGE-(Handset)
→
CHARGE-(Charger Unit)
→
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 Q2 of Handset.
Refer to Fig.101 in Power Supply Circuit (P.54).
22.4. 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;
·
Battery Low
Battery voltage: V(Batt) < 2.3V
The BBIC detects this level and "
" starts flashing and "battery alarm" starts ringing.
·
Power Down
Battery voltage: V(Batt) < 2.2V
The BBIC detects this level and power down.
57
KX-TCD410RUT / KX-A141RUT / KX-TCD412R UT / KX-A142RUT
23 CIRCUIT OPERATION (CHARGER UNIT)
23.1. Power Supply Circuit
The power supply is as shown.
24 SIGNAL ROUTE
58
KX-TCD410RUT / KX-A141RUT / KX-TCD412R UT / KX-A142RUT
25 CPU DATA (BASE UNIT)
25.1. IC2 (BBIC)
Pin
Descriptiojn
I/O
Hi
Hi-z
Low
Remarks
1
VDD
-
-
-
-
-
2
VSS
-
-
-
-
-
3
Data Bus
D.I/O
-
-
-
for Flash Memory
4
PA_Driver_Amp
D.O
PA-ON
-
PA-OFF
-
5
Data Bus
D.I/O
-
-
-
for Flash Memory
6
TX/RX SW
D.O
TX
-
RX
-
7
Data Bus
D.I/O
-
-
-
for Flash Memory
8
RX Data
D.I
Active
-
Active
-
9
Data Bus
D.I/O
-
-
-
for Flash Memory
10
PLL Strobe
D.O
Normal
-
Latch
-
11
Data Bus
D.I/O
-
-
-
for Flash Memory
12
PLL Data
D.O
Active
-
Active
-
13
PLL Clk
D.O
Active
-
Active
-
14
Address Bus
D.O
-
-
-
for Flash Memory
15
TX Data
A.O
Active
-
Active
-
16
Address Bus
D.O
-
-
-
for Flash Memory
17
(NO USE)
D.O
-
-
-
-
18
Address Bus
D.O
-
-
-
for Flash Memory
19
Address Bus
D.O
-
-
-
for Flash Memory
20
RF System Clk
D.O
Active
-
Active
-
21
VDD
-
-
-
-
-
22
VSS
-
-
-
-
-
23
RESET
A.I
Normal
-
Reset
-
24
VDDPM
A.O
-
-
-
-
25
VSSO
D.I
-
-
-
-
26
(NO USE)
-
-
-
-
-
27
LOAD
A.I
-
-
-
-
28
XTAL
A.I
-
-
-
10.368MHz
29
NC
-
-
-
-
-
30
VDDLR
A.I
-
-
-
-
31
LRB
D.I
-
-
-
-
32
NC
-
-
-
-
-
33
VDDA
-
-
-
-
-
34
VSSA
-
-
-
-
-
35
(NO USE)
-
-
-
-
-
36
Audio Out N
A.O
-
-
-
-
37
Audio Out P
A.O
-
-
-
-
38
(NO USE)
-
-
-
-
-
39
Bandgap Ref
A.I
-
-
-
-
40
Differential Line P
A.I
-
-
-
for Bell Clip
41
(NO USE)
-
-
-
-
-
42
Differential Line N
A.I
-
-
-
for Bell Clip
43
Audio In N
A.I
-
-
-
-
44
(NO USE)
-
-
-
-
-
45
ADC Ref
A.I
-
-
-
-
46
RSSI
A.I
-
-
-
-
47
(NO USE)
-
-
-
-
-
48
AD2
A.I
-
-
-
for Polarity
49
AD3
A.I
-
-
-
for Polarity
50
(NO USE)
-
-
-
-
-
51
PX.0
D.I
(I_PU)
-
-
-
52
Address Bus
D.O
-
-
-
for Flash Memory
53
(NO USE)
D.I
(I_PU)
-
-
-
54
Address Bus
D.O
-
-
-
for Flash Memory
55
(NO USE)
D.I
(I_PU)
-
-
-
56
Address Bus
D.O
-
-
-
for Flash Memory
57
(NO USE)
D.I
(I_PU)
-
-
-
58
Address Bus
D.O
-
-
-
for Flash Memory
59
VDD
-
-
-
-
-
60
VSS
-
-
-
-
-
61
Address Bus
D.O
-
-
-
for Flash Memory
62
Address Bus
D.O
-
-
-
for Flash Memory
59
KX-TCD410RUT / KX-A141RUT / KX-TCD412R UT / KX-A142RUT
Pin
Descriptiojn
I/O
Hi
Hi-z
Low
Remarks
63
Serial Data(I2C)
D.I/O
Data
-
Data
-
64
Serial Clk(I2C)
D.I/O
Active
-
Active
-
65
Address Bus
D.O
-
-
-
for Flash Memory
66
Address Bus
D.O
-
-
-
for Flash Memory
67
MODE
D.I
-
-
(Fixed)
-
68
WR
D.O
-
-
Write IC4
for Flash Memory
69
R2/P1.7
D.O
-
-
(Fixed)
-
70
Address Bus
D.O
-
-
-
for Flash Memory
71
Bell/Paging LED
D.O
LED ON
-
LED OFF
-
72
VBACK
A.I
-
-
-
-
73
VSS
-
-
-
-
-
74
Address Bus
D.O
-
-
-
for Flash Memory
75
Address Bus
D.O
-
-
-
for Flash Memory
76
DSPIN/P1.O
D.I
-
-
(Fixed)
77
Address Bus
D.O
-
-
-
for Flash Memory
78
DSPOUT/P1.1
D.I
(Fixed)
-
-
79
Address Bus
D.O
-
-
-
for Flash Memory
80
DSPCLK/P1.2
D.I
-
-
(Fixed)
81
Address Bus
D.O
-
-
-
for Flash Memory
82
DSPFRM/P1.3
D.O
-
-
(Fixed)
83
OE
D.O
-
-
Read IC4
for Flash Memory
84
VSS
-
-
-
-
-
85
VDD
-
-
-
-
-
86
Address Bus
D.O
-
-
-
for Flash Memory
87
Key IN
D.I
No Key
-
Key
-
88
(NO USE)
D.I
-
-
(I PD)
-
89
CE
D.O
-
-
IC4 Active
for Flash Memory
90
(NO USE)
D.O
-
-
-
-
91
(NO USE)
D.O
-
-
-
-
92
Data Bus
D.I/O
-
-
-
for Flash Memory
93
(NO USE)
D.I
-
-
(I PD)
-
94
(NO USE)
D.I
-
-
(I PD)
-
95
HOOK CTRL
D.O
Make
Break
-
96
Data Bus
D.I/O
-
-
-
for Flash Memory
97
(NO USE)
D.O
-
-
-
-
98
Data Bus
D.I/O
-
-
-
for Flash Memory
99
ANT1
D.O
ANT1 ON
-
ANT1 OFF
-
100
ANT2
D.O
ANT2 ON
-
ANT2 OFF
-
Note:
I_PU; Internal Pull-Up, I_PD; Internal Pull-Down
60
KX-TCD410RUT / KX-A141RUT / KX-TCD412R UT / KX-A142RUT
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