5 V-Powered
CMOS RS-232 Drivers/Receivers
ADM231L–ADM234L/ADM236L–ADM241L
FEATURES
Single 5 V power supply
Meets all EIA-232-E and V.28 specifications
120 kbps data rate
On-board dc-to-dc converters
±9 V output swing with 5 V supply
Small 1 µF capacitors
Low power shutdown ≤1 µA
±30 V receiver input levels
Latch-up free
ADM236L TYPICAL OPERATING CIRCUIT
+5V INPUT
C1+
C1–
C2+
C2–
V
CC
V+
+5V TO +10V
VOLTAGE
DOUBLER
+10V TO –10V
VOLTAGE
INVERTER
1µF
+6.3V
1µF
+6.3V
1µF
+6.3V
1µF
+16V
V–
1µF
+16V
T1
OUT
T2
OUT
T3
OUT
T4
OUT
R1
IN
R2
IN
R3
IN
SD
RS-232
INPUTS
2
RS-232
OUTPUTS
T1
IN
T2
IN
TTL/CMOS
INPUTS
1
T3
IN
T4
IN
R1
OUT
TTL/CMOS
OUTPUTS
R2
OUT
R3
OUT
T1
T2
APPLICATIONS
Computers
Peripherals
Modems
Printers
Instruments
T3
T4
R1
R2
R3
GENERAL DESCRIPTION
EN
The ADM2xx family of line drivers/receivers is intended for all
EIA-232-E and V.28 communications interfaces, especially in
applications in which 12 V is not available. The ADM236L and
ADM241L feature a low power shutdown mode that reduces
power dissipation to less than 5 µW, making them ideally suited
for battery-powered equipment. The ADM233L does not
require any external components and is particularly useful in
applications where printed circuit board space is critical.
All members of the ADM2xxL family, except the ADM231L and
ADM239L, include two internal charge pump voltage converters
that allow operation from a single 5 V supply. These parts convert
the 5 V input power to the ±10 V required for RS-232 output
Table 1. Selection Table
Part
Number
ADM231L
ADM232L
ADM233L
ADM234L
ADM236L
ADM237L
ADM238L
ADM239L
ADM241L
Rev. C
Information furnished by Analog Devices is believed to be accurate and reliable.
However, no responsibility is assumed by Analog Devices for its use, nor for any
infringements of patents or other rights of third parties that may result from its use.
Specifications subject to change without notice. No license is granted by implication
or otherwise under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
GND
ADM236L
1
INTERNAL 400kΩ PULL-UP RESISTOR ON EACH TTL/CMOS INPUT.
2
INTERNAL 5kΩ PULL-DOWN RESISTOR ON EACH RS-232 INPUT.
Figure 1.
levels. The ADM231L and ADM239L are designed to operate
from 5 V and 12 V supplies. An internal +12 V to −12 V charge
pump voltage converter generates the −12 V supply.
The ADM2xxL is an enhanced upgrade to the AD2xx family. It
features lower power consumption, faster slew rate, and the
ability to operate with smaller (1 µF) capacitors.
Power Supply Voltage
5 V and 7.5 V to 13.2 V
5V
5V
5V
5V
5V
5V
5 V and 7.5 V to 13.2 V
5V
No. of RS-232
Drivers
2
2
2
4
4
5
4
3
4
No. of RS-232
Receivers
2
2
2
0
3
3
4
5
5
External
Capacitors
2
4
None
4
4
4
4
2
4
Low Power
Shutdown (SD)
No
No
No
No
Yes
No
No
No
Yes
TTL
Three-State EN
No
No
No
No
Yes
No
No
Yes
Yes
No. of
Pins
14
16
20
16
24
24
24
24
28
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Tel: 781.329.4700
Fax: 781.461.3113
© 2005 Analog Devices, Inc. All rights reserved.
00070-0-015
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