KX-AT7730RU (serv.man2) — Panasonic Telephone Service Manual (repair manual). Page 10

View Panasonic KX-AT7730RU (serv.man2) Service Manual online

10
KX-AT7730 Series
4.2.4.
TONE GENERATION CIRCUIT
Function:
This circuit generates all system tones including COL, extension, busy, DTMF signals and key in confirmation tones during the 
power failure mode and is comprised of IC1(DTMF Generator) and IC5 (Analog Switch).
Circuit Operation:
For an output of a single row tone, the row terminal and the each column terminals intersecting with it are required to be brought a 
low state. For a dual tone output, one row terminal and one column terminal are brought to low state.
CONDITION
IC1 pin52
IC5 SWA
IC1 pin53
IC5 SWB
IC1 pin54
IC5 SWC
IC1 pin55
IC5 SWD
Ringing
L
OFF
L
OFF
L
OFF
H
ON
Call Waiting
L
OFF
L
OFF
H
ON
L
OFF
Tone Dial (Handset)
H
ON
H
ON
L
OFF
L
OFF
Tone Dial (Speakerphone) H
ON
L
OFF
H
ON
L
OFF
Circuit Diagram
C28
R31
R30
C29
C84
C31
Q8
R84
IC1
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
R124
R123
A5V
T_CONT1
T_CONT3
T_CONT4
R81
C81
T_CONT2
T_CONT1
T_CONT2
T_CONT3
T_CONT4
C63
C61
AG
C66
AG
R80
CN3
1
+
2
-
C67
R85
AG
Parity Circuit Board 1
P3_5
P3_4
P3_3/*INT3
P2_7
P2_6
P2_5
P2_4
P2_3
P2_2
P2_1
P2_0
P3_6
P3_1
P8_6
P8_5
P8_4
P8_3
P8_2
P8_1
P8_0
P6_7
P6_6/TXD2
P6_5/CLK2
P4_5
P1_7
P1_6
P1_5
P1_4
P1_3
P1_2
P1_1
P1_0
P0_
7/DA1
P0_
6/DA0
P0_5
T_CONT1
P0_3
P0_2
P0_1
P0_0
P6_4
P6_3
P6_2
P6_1
P6_0
P5_7
P5_6
P3_2
P3_0
P4_2/VREF
MODE
HS_MUTE
P4_4/XCOUT
*RESET
P4_7/XOUT
VSS/AVSS
P4_6/XIN
VCC/AVCC
P5_4
P5_3
P5_2
P5_1
P5_0
P3_7
IC5
1
I/O1
2
O/I1
12
CONT4
13
CONT1
3
O/I2
14
VDD
4
I/O2
11
I/O4
5
CONT2
10
O/I4
6
CONT3
9
O/I3
7
VSS
8
I/O3
R82
R86
R87
C82
NC
AG
D3.3V
R88
AG
D3.3V
AG
R296
NC
AG
AG
C85
C86
IC8
1
IN/OUT
2
OUT/IN
3
GND
5
VCC
4
CONT
AG
R89
68k
D3.3V
R144
470
R90
470
AG
AG1
K1
K2
N1
N2
N3
N4
CN7-6
CN8-1
CN8-5
CN7-7
CN7-3
CN8-2
Q18
SW1
4
C
1
2
3
5
6
RING_OFF
CN8
CN7
C6
C7
R9
R10
R7
C5
NC
AG
R8
AG
T1
1
6
3
4
2
Q3
C4
C14
IC3
1
RR
2
RTX
3
TXI
4
TXO
5
TLI
23
XDC
24
VLC
25
ACF
26
RXO
27
RXI
6
TLO
7
RLI
8
RLO
9
MCI
10
MCO
12
CP2
13
XDI
14
SKG
18
*CS
19
SKI
20
VCC
21
VB
22
GND
15
SKO
16
V+
17
AGC
11
CP1
28
RRX
L4
R79
R78
+6V
AG
0
R61
Page of 45
Display

Click on the first or last page to see other KX-AT7730RU (serv.man2) service manuals if exist.