23

LTC2846

sn2846 2846fs

Figure 35. Cable-Selectable Multiprotocol DTE/DCE Port with DB-25 Connector

TYPICAL APPLICATIO S

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

GND

2846 F35

C2

1

µF

R1

13k

C1

1

µF

C6

10

µF

C3

1

µF

C4

3.3

µF

D4

5V

SHDN

3.3V

CHARGE

PUMP

BOOST

SWITCHING

REGULATOR

L1

5.6

µH

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

15

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

10

µF

C9

1

µF

C7

1

µF

C8

1

µF

M0

M1

M2

DCE/DTE

11

12

13

14

D1

D2

D3

R1

R2

R3

T

T

T

T

T

C10

1

µF

R2

4.3k

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

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.