11

LTC1344

Cable Selectable Multiprotocol DTE Port with DB-25 Connector

LTC1343

1

2

4

3

8

5

6

7

9

10

39

38

37

36

35

34

33

32

31

30

29

28

27

26

21

19

18

17

12

13

14

15

16

40

23

20

22

11

25

CTRL

LATCH

INVERT

423 SET

DCE

M2

M1

M0

R2

R3

R4

R1

100k

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

DCD A

DCD B

DSR A

DSR B

CTS A

CTS B

DCD A

DCD B

DTR A

DTR B

RTS A

RTS B

DTE

DCE

20 22

23 24 1

M0

M1

M2

DCE/

DTE

13

12

11

38

C6

100pF

C7

100pF

19

17

18

15

16

10

9

7

6

4

5

2

44

C2

1

µF

C4

3.3

µF

C10

1

µF

C13

3.3

µF

C5

1

µF

C1

1

µF

43

42

41

14

5V

2

14

24

11

15

12

17

9

3

16

7

1

4

19

20

23

8

10

6

22

5

13

25

21

18

1344 TA03

DB-25 CONNECTOR

LTC1344

C8

100pF

R1

C3

1

µF

GND

LB

EC

24

LTC1343

1

2

4

3

8

5

6

7

9

10

39

38

37

36

35

34

33

32

31

30

29

28

27

26

21

19

18

17

12

13

14

15

16

40

23

20

22

11

25

CTRL

LATCH

INVERT

423 SET

DCE

M2

M1

M0

R2

R3

R4

R2

100k

44

C12

1

µF

C9

1

µF

43

42

41

C11

1

µF

GND

LB

EC

R1

DTE_TXD/DCE_RXD

DTE_SCTE/DEC_RXC

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

LB

SGND

SHIELD

CTS A

CTS B

DSR A

DSR B

CHARGE

PUMP

CHARGE

PUMP

D1

D2

D3

D4

TXC A

TXC B

SCTE A

SCTE B

TXD A

TXD B

TXC A

TXC B

R5

10k

R4

10k

DCE/DTE

M1

M0

D1

D2

D3

D4

24

R3

10k

CABLE WIRING FOR MODE SELECTION

MODE

PIN 18

PIN 21

V.35

PIN 7

PIN 7

EIA-530, RS449,

NC

PIN 7

V.36, X.21

RS232

PIN 7

NC

CABLE WIRING FOR DTE/DCE

SELECTION

MODE

PIN 25

DTE

PIN 7

DCE

NC

21

LATCH

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.