Datasheet

19
LTC1546
Figure 33. Cable-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
D2
D1
LTC1544
D3
R2
R1
R4
R3
LTC1546
DTE_TXD/DCE_RXD
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
DTE_RXD/DCE_TXD
NC
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
V
CC
V
EE
GND
2
14
24
11
15
12
17
9
3
1
25
21
18
4
19
20
8
23
10
6
22
5
13
7
16
1546 F33
C2
1µF
C1
1µF
C5
1µF
C3
1µF
C4
3.3µF
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
V
CC
5V
+
28
3
1
2
4
11
12
13
14
1
2
3
4
5
6
7
8
9
NC
10
INVERT
15
17
16
18
19
20
21
22
23
24
25
NC
27
26
25
26
27
28
M0
M1
M2
DCE/DTE
11
12
13
14
DTE
DCE
MODE
V.35
RS449, V.36
RS232
PIN 18
PIN 7
NC
PIN 7
PIN 21
PIN 7
PIN 7
NC
CABLE WIRING FOR MODE SELECTION
MODE PIN 25
DTE PIN 7
DCE NC
CABLE WIRING FOR
DTE/DCE SELECTION
C11
1µF
C10
1µF
C9
1µF
CHARGE
PUMP
5
6
7
8
9
10
24
23
22
21
20
19
18
17
16
15
D1
T
T
T
T
T
D2
D3
R1
R2
R3
TXD A
TXD B
SCTE A
SCTE B
TYPICAL APPLICATIO S
U
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.