HIN232, HIN236, HIN237, HIN238, HIN239, HIN240, HIN241
Applications
+5V
-
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.
+
16
DTR (20) DATA
TERMINAL READY
1
+
C1
1µF
2
3
4
DSRS (24) DATA
SIGNALING RATE
SELECT
-
HIN232
6
+
-
+
C2
1µF
RS-232
INPUTS AND OUTPUTS
5
-
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 5kΩ resistor
connected to V+.
T1
11
14
TD
TD (2) TRANSMIT DATA
T2
10
12
7
RTS (4) REQUEST TO SEND
RD (3) RECEIVE DATA
TTL/CMOS RTS
INPUTS AND
13
RD
OUTPUTS
R2
R1
9
8
CTS
CTS (5) CLEAR TO SEND
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.
15
SIGNAL GROUND (7)
FIGURE 9. SIMPLE DUPLEX RS-232 PORT WITH CTS/RTS
HANDSHAKING
1
4
+
+
C1
C2
HIN232
T1
5
1µF
3
1µF
-
-
11
14
TD
RTS
RD
TD (2) TRANSMIT DATA
RTS (4) REQUEST TO SEND
RD (3) RECEIVE DATA
T2
10
12
7
TTL/CMOS
INPUTS AND
OUTPUTS
13
R2
R1
9
8
CTS
CTS (5) CLEAR TO SEND
15
16
6
6
2
2
C4
C3
+5V
-
-
V- V+
RS-232
INPUTS AND OUTPUTS
2µF
2µF
16
4
HIN232
T1
1
+
+
C1
1µF
C2
1µF
5
3
-
-
11
14
DTR
DSRS
DCD
R1
DTR (20) DATA TERMINAL READY
DSRS (24) DATA SIGNALING RATE SELECT
DCD (8) DATA CARRIER DETECT
R1 (22) RING INDICATOR
T2
10
12
7
TTL/CMOS
INPUTS AND
OUTPUTS
13
R2
R1
9
8
15
SIGNAL GROUND (7)
FIGURE 10. COMBINING TWO HIN232s FOR 4 PAIRS OF RS-232 INPUTS AND OUTPUTS
12
ISSI [ INTEGRATED SILICON SOLUTION, INC ]
