7
January 2005 © TOSHIBA TEC
e-STUDIO170F Circuit Description
7 - 55
7.4.1
Line Path Switching Control Circuit
US/CA models, SG/HK models
Fig.7-37
The line path switching control circuit consists of the CML relay (RLY2) and analog switch (IC51), the
ASIC (I/O port: IC38) on the Main PBA, and other peripheral devices. It changes the path for facsimile
send/receive signals and connects it to each control circuit.
The CML relay is switched according to the CML signal output from the ASIC on the Main PBA. When
the CML signal goes HIGH, Q51 turns on and +12V is applied to the CML relay to turn on.
The analog switch is switched according to the CML signal and ATT3DB signal. When the CML signal
or ATT3DB signal goes HIGH, the analog switch turns on.
Turning on the CML relay and analog switch allows the MODEM to be connected to the line.
Signal Name
Type
Active
Description
Destination
CML
O
H
CML relay control signal
Q51, IC51
ATT3DB
O
H
Attenuator control signal
IC51
IC38
ASIC
(I/O port)
CML
ATT3DB
TXOUT
RXIN
3
1
2
2
7
1
6
7
5
6
6
AG
Q51
CN10
Lb
La
Line
0
1
0
1
12
8
9
1
4
10
3
+12V
RLY2
CML relay
C5
T1
IC53
R59
R66
IC52
IC53
R71
R4
4
3
CN11
a2
b2
External
TEL
3
4
CN8
HS1
HS2
TEL PBA
(Handset)
6
5
3
1
2
13
14
15
4
10
9,11
6
3
2
32
28,29
1
54
49
Main PBA
NCU PBA
AG
Ring signal
detection
circuit
IC53
MODEM
0
1
0
1
0
1
R68
IC51
Analog
switch
CN9
CN16
R67
Summary of Contents for ESTUDIO170F
Page 2: ... 2005 TOSHIBA TEC CORPORATION All rights reserved ...
Page 192: ...e STUDIO170F Function Settings January 2005 TOSHIBA TEC 4 132 ...
Page 214: ...e STUDIO170F Mechanical Description January 2005 TOSHIBA TEC 5 22 ...
Page 308: ...e STUDIO170F Circuit Description January 2005 TOSHIBA TEC 7 78 ...
Page 372: ...e STUDIO170F Removal Replacement Adjustment January 2005 TOSHIBA TEC 8 64 ...
Page 490: ...e STUDIO170F Appendix January 2005 TOSHIBA TEC 12 8 ...
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