Datasheet

17
LTC1546
Figure 31. Controller-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
D2
D1
LTC1544
D3
R2
R1
R4
R3
LTC1546
DTE_TXD/DCE_RXD
DTE_SCTE/DCE_RXC
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_LL
M0
M1
M2
DCE/DTE
V
CC
V
DD
V
CC
V
EE
GND
2
14
24
11
15
12
17
9
3
1
4
19
20
8
23
10
6
22
5
13
18
7
16
1546 F31
C2
1µF
C1
1µF
C5
1µF
C3
1µF
C4
3.3µF
SCTE B
RTS A
RTS B
DTR A
DTR B
CTS A
CTS B
DSR A
DSR B
CTS A
CTS B
LL A
SG
SHIELD
DB-25
CONNECTOR
DCD A
DCD B
DSR A
DSR B
RTS A
RTS B
LL A
DCD A
DCD B
DTR A
DTR B
D4
V
CC
5V
CHARGE
PUMP
+
28
3
1
2
4
5
6
7
8
9
10
11
12
13
14
1
2
3
4
5
6
7
8
10
9
INVERT
15
16
17
18
19
20
21
22
23
24
25
NC
27
26
25
24
23
22
21
20
19
18
17
16
15
26
27
28
C11
1µF
C10
1µF
C9
1µF
M0
M1
M2
DCE/DTE
11
12
13
14
M0
M1
M2
DCE/DTE
D1
T
T
T
T
T
D2
D3
R1
R2
R3
TXD A
TXD B
TXC A
RXC A
RXD A
TXC B
RXC B
RXD B
TXC A
SCTE A
TXD A
TXC B
SCTE B
TXD B
SCTE A
RXC B
RXD A
DTE DCE
RXD B
RXC A
TYPICAL APPLICATIO S
U