One Technology Way, P.O. Box 9106, Norwood. MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
REV. 0
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
High Speed, +5 V, 0.1 µF
CMOS RS-232 Drivers/Receivers
FEATURES
200 kB/s Transmission Rate
Small (0.1 µF) Charge Pump Capacitors
Single 5 V Power Supply
Meets All EIA-232-E and V.28 Specifications
Two Drivers and Two Receivers
On-Board DC-DC Converters
±9 V Output Swing with +5 V Supply
±30 V Receiver Input Levels
Pin Compatible with MAX222/MAX232A/MAX242
APPLICATIONS
Computers
Peripherals
Modems
Printers
Instruments
ORDERING GUIDE
Model Temperature Range Package Option
ADM222AN –40°C to +85°C N-18
ADM222AR –40°C to +85°C R-18W
ADM232AAN –40°C to +85°C N-16
ADM232AARN –40°C to +85°C R-16N
ADM232AARW –40°C to +85°C R-16W
ADM242AN –40°C to +85°C N-18
ADM242AR –40°C to +85°C R-18W
* INTERNAL 400kΩ PULL-UP RESISTOR
ON EACH TTL/MOS INPUT
** INTERNAL 5kΩ PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
V
CC
+5V TO +10V
VOLTAGE DOUBLER
+5V TO –10V
VOLTAGE INVERTER
C1+
C1–
V+
V–
C2+
C2–
T1
ADM2xx
T2
R1
R2
0.1µF
0.1µF
0.1µF
GND
TTL/CMOS
OUTPUTS
R1
OUT
R2
OUT
T1
OUT
T2
OUT
R1
IN
R2
IN
T1
IN
T2
IN
TTL/CMOS
INPUTS*
RS-232
OUTPUTS
RS-232
INPUTS**
0.1µF
+5V INPUT
0.1µF
EN
SHDN
(ADM242)
(ADM222, ADM242)
ADM222/ADM232A/ADM242*
FUNCTIONAL BLOCK DIAGRAM
GENERAL DESCRIPTION
The ADM222, ADM232A, ADM242 are a family of high speed
RS-232 line drivers/receivers offering transmission rates up to
200 kB/s. Operating from a single +5 V power supply, a highly
efficient on-chip charge pump using small (0.1 µF) external
capacitors allows RS-232 bipolar levels to be developed. Two
RS-232 drivers and two RS-232 receivers are provided on each
device.
The devices are fabricated on BiCMOS, an advanced mixed
technology process which combines low power CMOS with high
speed bipolar circuitry. This allows for transmission rates up to
200 kB/s yet minimizes the quiescent power supply current to
under 5 mA.
The ADM232A is a pin-compatible, high speed upgrade for the
AD232 and for the ADM232L. It is available in 16-pin DIP and
in both narrow and wide surface mount (SOIC) packages.
The ADM222 contains an additional shutdown (SHDN) func-
tion which may be used to disable the device thereby reducing
the supply current to 0.1 µA. During shutdown, all transmit/
receive functions are disabled. The ADM222 is available in
18-pin DIP and in a wide surface mount (SOIC) package.
The ADM242 combines both shutdown (SHDN) and enable
(EN) functions. The shutdown function reduces the supply
curent to 0.1 mA. During shutdown, the transmitters are
disabled but the receivers continue to operate normally. The
enable function allows the receiver outputs to be disabled
thereby facilitating sharing a common bus. The ADM242 is
available in 18-pin DIP and in a wide surface mount (SOIC)
package.
*Protected by U.S. Patent No. 5,237,209.