
15
LTC1545
TYPICAL APPLICATIONS
U
Figure 24. Controller-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
10
17
18
D2
D1
LTC1545
D3
R2
R1
R3
VCC
VDD
VEE
GND
D4
1,19
2,20
3
4
5
6
7
8
9
R4EN
D4ENB
15
16
NC
24
23
22
25
26
27
28
29
30
31
32
33
34
35
36
M0
M1
M2
DCE/DTE
11
12
13
14
D5
21
R4
R5
18
*
*OPTIONAL
21
25
LL
RL
TM
RI
D2
LTC1543
DTE_TXD/DCE_RXD
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
DTE_RXD/DCE_TXD
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
DTE_DCD/DCE_DCD
DTE_DSR/DCE_DTR
DTE_CTS/DCE_RTS
DTE_LL/DCE_RI
DTE_RI/DCE_LL
DTE_TM/DCE_RL
DTE_RL/DCE_TM
DTE_SCTE/DCE_RXC
M0
M1
M2
DCE/DTE
VCC
5V
2
14
24
11
15
12
17
9
3
1
4
19
20
8
23
10
6
22
5
13
7
16
1544 F24
D3
R2
R1
R3
D1
C2
1
F
C1
1
F
C5
1
F
C3
1
F
C4
3.3
F
TXD A
TXD B
SCTE A
SCTE B
RXD A
RXD B
RXC A
RXC B
RXC A
RXC B
RXD A
RXD B
RTS A
RTS B
DTR A
DTR B
CTS A
CTS B
DSR A
DSR B
CTS A
CTS B
SG
SHIELD
DB-25
CONNECTOR
TXC A
TXC B
SCTE A
SCTE B
TXD A
TXD B
TXC A
TXC B
DCD A
DCD B
DSR A
DSR B
RTS A
RTS B
DCD A
DCD B
DTR A
DTR B
16
10
9
7
6
4
3
8
11
12
13
5
2
15 18 17 19 20 22
LTC1344A
C6
100pF
C7
100pF
C8
100pF
VCC
5V
23 24
14
1
DCE/DTE
M2
M1
M0
CHARGE
PUMP
+
28
3
1
2
4
5
6
7
8
9
10
11
12
13
14
27
26
25
24
23
22
21
20
19
18
17
16
15
VEE
DCE/DTE
M0
M1
M2
DTE
DCE
21
LATCH
C12
1
F
C13
1
F
C11
1
F
C10
1
F
C9
1
F
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.