Datasheet

20
LTC2846
sn2846 2846fs
Figure 32. Controller-Selectable DCE Port with DB-25 Connector
TYPICAL APPLICATIO S
U
D2
D1
LTC2844
CTS
DSR
DTR
DCD
RTS
D3
R2
R1
R4
R3
LTC2846
LL
RXD
RXC
TXC
SCTE
TXD
M0
M1
M2
DCE/DTE
V
CC
V
DD
V
CC
V
EE
GND
3
16
17
9
15
12
24
11
2
1
5
13
6
8
22
10
20
23
4
19
18
7
14
2846 F32
C2
1µF
R1
13k
C1
1µF
C6
10µF
C3
1µF
C4
3.3µF
RXC B
CTS A (106)
CTS B
DSR A (107)
DSR B
RTS A (105)
RTS B
LL A (141)
SGND (102)
SHIELD (101)
DB-25 FEMALE
CONNECTOR
DCD A (109)
DCD B
DTR A (108)
DTR B
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
M0
M1
M2
11
12
13
14
D1
D2
D3
R1
R2
R3
RXD A (104)
RXD B
SCTE A (113)
TXD A (103)
TXC B
SCTE B
TXD B
RXC A (115)
T
T
T
T
T
C10
1µF
R2
4.3k
V
CC
5V
17
V
IN
3.3V
TXC A (114)