17

LTC1546

Figure 31. Controller-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector

D2

D1

LTC1544

D3

R2

R1

R4

R3

LTC1546

DTE_TXD/DCE_RXD

DTE_SCTE/DCE_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

DTE_LL/DCE_LL

M0

M1

M2

DCE/DTE

GND

2

14

24

11

15

12

17

9

3

1

4

19

20

8

23

10

6

22

5

13

18

7

16

1546 F31

C2

1

µF

C1

1

µF

C5

1

µF

C3

1

µF

C4

3.3

µF

SCTE B

RTS A

RTS B

DTR A

DTR B

CTS A

CTS B

DSR A

DSR B

CTS A

CTS B

LL A

SG

SHIELD

DB-25

CONNECTOR

DCD A

DCD B

DSR A

DSR B

RTS A

RTS B

LL A

DCD A

DCD B

DTR A

DTR B

D4

5V

CHARGE

PUMP

28

3

1

2

4

5

6

7

8

9

10

11

12

13

14

1

2

3

4

5

6

7

8

10

9

INVERT

15

16

17

18

19

20

21

22

23

24

25

NC

27

26

25

24

23

22

21

20

19

18

17

16

15

26

27

28

C11

1

µF

C10

1

µF

C9

1

µF

M0

M1

M2

DCE/DTE

11

12

13

14

M0

M1

M2

DCE/DTE

D1

T

T

T

T

T

D2

D3

R1

R2

R3

TXD A

TXD B

TXC A

RXC A

RXD A

TXC B

RXC B

RXD B

TXC A

SCTE A

TXD A

TXC B

SCTE B

TXD B

SCTE A

RXC B

RXD A

DTE

DCE

RXD B

RXC A

TYPICAL APPLICATIO S