9

LTC1344A

D2

D1

LTC1544

D3

R2

R1

R4

R3

D2

LTC1343

DTE_LL/DCE_TM

DTE_TXC/DCE_TXC

DTE_RXC/DCE_SCTE

DTE_RXD/DCE_TXD

DTE_TM/DCE_LL

DTE_RTS/DCE_CTS

DTE_DTR/DCE_DSR

DTE_DCD/DCE_DCD

DTE_DSR/DCE_DTR

DTE_CTS/DCE_RTS

DTE_RL/DCE_RL

DTE_TXD/DCE_RXD

DTE_SCTE/DCE_RXC

CTRL

LATCH

INVERT

423SET

GND

DCE

M2

M1

M0

EC

GND

2

18

14

24

11

15

12

17

9

3

1

4

19

20

8

23

10

6

22

5

13

21

7

16

25

1344A TA04

D3

D4

R2

R3

R4

D1

C2

1

µF

C1

1

µF

C5

1

µF

C3

1

µF

C4

3.3

µF

LL A

TXD A

TXD B

SCTE A

SCTE B

TM A

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

RL 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

RL 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

LATCH

C6

100pF

C7

100pF

C8

100pF

5V

23 24

14

21

1

CHARGE

PUMP

44

3

1

2

4

5

8

6

7

9

10

12

13

14

15

16

20

22

11

1

R1

100k

2

3

4

5

6

7

8

10

9

INVERT

15

16

17

18

19

20

21

22

23

24

25

NC

43

42

41

39

38

37

36

35

34

33

32

31

30

29

28

27

26

21

19

18

17

24

26

27

28

C12

1

µF

M0

M1

M2

DCE/DTE

DCE/DTE

M2

M1

M0

11

12

13

14

DTE

DCE

R1

25

40

23

LB

LB

TM A

LL A

C13

1

µF

C11

1

µF

C10

1

µF

C9, 1

µF

Controller Selectable Multiprotocol DTE/DCE Port with DB-25 Connector