Datasheet
19
LTC1544
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_SCTE/DCE_RXC
M0
M1
M2
DCE/DTE
V
CC
V
DD
NC
NC
V
CC
V
EE
GND
2
V
CC
14
24
11
15
12
17
9
3
1
25
21
18
4
19
20
8
23
10
6
22
5
13
7
16
1544 F26
D3
R2
R1
R3
D1
C2
1µF
C1
1µF
C5
1µF
C3
1µF
C4
3.3µF
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
DCE/DTE
M1
M0
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
D4
16109764
3 8 11 12 13
5
2
15 18 17 19 20 22
LTC1344A
C6
100pF
C7
100pF
C8
100pF
V
CC
V
CC
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
9
10
INVERT
15
17
16
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
V
EE
M0
M1
M2
DCE/DTE
11
12
13
14
DTE
DCE
MODE PIN 18 PIN 21
V.35 PIN 7 PIN 7
RS449, V.36 NC PIN 7
RS232 PIN 7 NC
CABLE WIRING FOR MODE SELECTION
MODE PIN 25
DTE PIN 7
DCE NC
CABLE WIRING FOR
DTE/DCE SELECTION
21
LATCH
C12
1µF
C13
1µF
C11
1µF
C10
1µF
C9
1µF
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.
Figure 26. Cable-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
TYPICAL APPLICATIO S
U