Datasheet

23
LTC2846
sn2846 2846fs
Figure 35. Cable-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector
TYPICAL APPLICATIO S
U
D2
D1
LTC2844
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
DTE_DSR/DCE_DTR
DTE_DCD/DCE_DCD
DTE_CTS/DCE_RTS
D3
R2
R1
R4
R3
LTC2846
DTE_TXD/DCE_RXD
DTE_SCTE/DCE_RXC
DTE_TXC/DCE_TXC
DTE_RXC/DCE_SCTE
DTE_RXD/DCE_TXD
M0
M1
M2
DCE/DTE
V
CC
V
DD
V
CC
V
EE
GND
2846 F35
C2
1µF
R1
13k
C1
1µF
C6
10µF
C3
1µF
C4
3.3µF
D4
V
CC
5V
SHDN
V
IN
3.3V
CHARGE
PUMP
BOOST
SWITCHING
REGULATOR
L1
5.6µH
+
33
7
35
4
36
D1
MBR0520
3
5
6
8
9
10
11
12
13
14
15
16
18
19
NC
1
2
3
4
5
6
7
8
10
9
NC
V
IN
15
V
IN
3.3V
16
17
18
19
20
21
22
23
24
25
32
31
30
29
28
27
26
25
24
23
22
21
20
26
27
28
C5
10µF
C9
1µF
C7
1µF
C8
1µF
M0
M1
M2
DCE/DTE
11
12
13
14
D1
D2
D3
R1
R2
R3
T
T
T
T
T
C10
1µF
R2
4.3k
V
CC
5V
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
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
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
TXD A
TXD B
SCTE A
SCTE B
17
V
IN
3.3V
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.