
17
LTC1544
Figure 24. Controller-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
D2
D1
LTC1544
D3
R2
R1
R4
R3
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_LL
DTE_SCTE/DCE_RXC
M0
M1
M2
DCE/DTE
VCC
VDD
VCC
VEE
GND
2
14
24
11
15
12
17
9
3
1
4
19
20
8
23
10
6
22
5
13
18
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
LL A
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
LL A
DCD A
DCD B
DTR A
DTR B
D4
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
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
VEE
M0
M1
M2
DCE/DTE
M2
M1
M0
11
12
13
14
DTE
DCE
21
LATCH
C12
1
F
C13
1
F
C11
1
F
C10
1
F
C9
1
F
TYPICAL APPLICATIO S
U