ICL232 Datasheet, PDF (5/5 Pages) Intersil Corporation – +5V Powered, Dual RS-232 Transmitter/Receiver

ICL232
V_CC
R_XIN
-30V < R_XIN < +30V _5kΩ
GND
R_OUT
GND < V_ROUT < V_CC
FIGURE 8. RECEIVER
T1_IN, T2_IN
OR
R1_IN, R2_IN
T1_OUT, T2_OUT
OR
R1_OUT, R2_OUT
t_PHL
t_PLH
V_OH
V_OL
Average Propagation Delay =
t_{PHL +} t_PLH
2
FIGURE 9. PROPAGATION DELAY DEFINITION
Applications
The ICL232 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 conven-
tional 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 10. 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+.
+5V
1
C1 ⁺
1µF _- 3
4
C2 ⁺
1µF _- 5
16
ICL232
11 ^T1
TD
T2
INPUTS
10
RTS
OUTPUTS
12
TTL/CMOS RD
CTS ^{9 R2}
R1
- C3
+ ^1µF
2
5kΩ _{CTR (20) DATA}
TERMINAL READY
5kΩ _{DSRS (24) DATA}
SIGNALING RATE
6
- _C4
SELECT
+ 1µF ^RS-232
INPUTS AND OUTPUTS
14
TD (2) TRANSMIT DATA
7 _{RTS (4) REQUEST TO SEND}
13
RD (3) RECEIVE DATA
8 _{CTS (5) CLEAR TO SEND}
15
SIGNAL GROUND (7)
FIGURE 10. SIMPLE DUPLEX RS-232 PORT WITH CTS/RTS
HANDSHAKING
In applications requiring four RS-232 inputs and outputs
(Figure 11), 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 res-
ervoir 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.
1
C1 ⁺
1µF _- 3
ICL232
4
+ _C2
5 _- 1µF
INPUTS
OUTPUTS
TTL/CMOS
11
TD
10
RTS
T1
14
TD (2) TRANSMIT DATA
T2
7 _{RTS (4) REQUEST TO SEND}
12
13
RD
RD (3) RECEIVE DATA
CTS ^{9 R2}
R1
8 _{CTS (5) CLEAR TO SEND}
15
C4 _-
2µF
6
2
V- V+
6
2
C3 _-
2 µF
16
+5V
RS-232
INPUTS AND
OUTPUTS
ICL232
1
C1 ⁺
1µF _- 3
INPUTS
OUTPUTS
TTL/CMOS
DTR
DSRS
DCD
R1
11 ^T1
T2
10
12
R2
9
R1
4
+ _C2
5 _- 1µF
14 DTR (20) DATA TERMINAL
READY
7 DSRS (24) DATA SIGNALING
RATE SELECT
13 _{DCD (8) DATA CARRIER}
DETECT
8 _{R1 (22) RING INDICATOR}
15
SIGNAL GROUND (7)
FIGURE 11. COMBINING TWO ICL232s FOR 4 PAIRS OF RS-232 INPUTS AND OUTPUTS
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