3-13

Applications

The HIN2XX may be used for all RS-232 data terminal and

communication links. It is particularly useful in applications

where

±12V power supplies are not available for

conventional RS-232 interface circuits. The applications

presented represent typical interface configurations.

A simple duplex RS-232 port with CTS/RTS handshaking is

illustrated in Figure 9. Fixed output signals such as DTR

(data terminal ready) and DSRS (data signaling rate select)

is generated by driving them through a 5k

Ω resistor

connected to V+.

In applications requiring four RS-232 inputs and outputs

(Figure 10), note that each circuit requires two charge pump

capacitors (C1 and C2) but can share common reservoir

capacitors (C3 and C4). The benefit of sharing common

reservoir capacitors is the elimination of two capacitors and

the reduction of the charge pump source impedance which

effectively increases the output swing of the transmitters.

-

+

-

+

-

+

DTR (20) DATA

TERMINAL READY

DSRS (24) DATA

SIGNALING RATE

RS-232

INPUTS AND OUTPUTS

TD (2) TRANSMIT DATA

RTS (4) REQUEST TO SEND

RD (3) RECEIVE DATA

CTS (5) CLEAR TO SEND

SIGNAL GROUND (7)

15

8

13

7

14

16

-

+

6

R2

R1

T2

T1

9

12

10

11

4

5

3

1

HIN232

C1

1

µF

C2

1

µF

TD

RTS

RD

CTS

SELECT

+5V

INPUTS AND

OUTPUTS

TTL/CMOS

FIGURE 9. SIMPLE DUPLEX RS-232 PORT WITH CTS/RTS

HANDSHAKING

2

FIGURE 10. COMBINING TWO HIN232s FOR 4 PAIRS OF RS-232 INPUTS AND OUTPUTS

-

+

RS-232

INPUTS AND OUTPUTS

DTR (20) DATA TERMINAL READY

DSRS (24) DATA SIGNALING RATE SELECT

DCD (8) DATA CARRIER DETECT

R1 (22) RING INDICATOR

SIGNAL GROUND (7)

15

8

13

7

14

2

-

4

R2

R1

T2

T1

9

12

10

11

3

1

HIN232

C1

1

µF

DTR

DSRS

DCD

R1

+5V

INPUTS AND

OUTPUTS

TTL/CMOS

-

+

-

+

TD (2) TRANSMIT DATA

RTS (4) REQUEST TO SEND

RD (3) RECEIVE DATA

CTS (5) CLEAR TO SEND

8

13

7

14

15

R2

R1

T2

T1

9

12

10

11

4

5

3

1

HIN232

C1

1

µF

C2

1

µF

TD

RTS

RD

CTS

INPUTS AND

OUTPUTS

TTL/CMOS

-

+

5

C2

1

µF

16

C3

2

µF

6

2

6

V- V+

-

C4

2

µF

16

HIN230 thru HIN241