a
High-Speed, 5 V, 0.1 F
CMOS RS-232 Driver/Receivers
ADM202/ADM203
FEATURES
120 kB Transmission Rate
ADM202: Small (0.1 F) Charge Pump Capacitors
ADM203: No External Capacitors Required
Single 5 V Power Supply
Meets 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
Low Power BiCMOS: 2.0 mA ICC
؎30 V Receiver Input Levels
APPLICATIONS
Computers
Peripherals
Modems
Printers
Instruments
FUNCTIONAL BLOCK DIAGRAMS
5V INPUT
0.1F
6.3V
0.1F
16V
C1+
C1–
C2+
C2–
+5V TO +10V
VOLTAGE
DOUBLER
+10V TO –10V
VOLTAGE
INVERTER
T1IN
The ADM202/ADM203 is a two-channel RS-232 line driver/
receiver pair designed to operate from a single 5 V power supply. A highly efficient on-chip charge pump design permits
RS-232 levels to be developed using charge pump capacitors as
small as 0.1 µF. The capacitors are internal to the package on
the ADM203 so no external capacitors are required. These
converters generate ± 10 V RS-232 output levels.
The ADM202/ADM203 meets or exceeds the EIA-232-E and
V.28 specifications. Fast driver slew rates permit operation up to
120 kB while high-drive currents allow for extended cable lengths.
An epitaxial BiCMOS construction minimizes power consumption to 10 mW and also guards against latch-up. Overvoltage
protection is provided allowing the receiver inputs to withstand
continuous voltages in excess of ± 30 V. In addition, all pins
contain ESD protection to levels greater than 2 kV.
The ADM202 is available in 16-lead DIP and both narrow and
wide SOIC packages. The ADM203 is available in a 20-lead
DIP package.
V+
0.1F
6.3V
0.1F
6.3V
V–
0.1F
16V
T1OUT
T1
RS-232
OUTPUTS
TTL/CMOS
INPUTS*
T2IN
T2OUT
T2
R1OUT
R1
R1IN
R2
R2IN
RS-232
INPUTS**
TTL/CMOS
OUTPUTS
R2OUT
ADM202
GND
GENERAL DESCRIPTION
VCC
*INTERNAL 400k⍀ PULL-UP RESISTOR ON EACH TTL/CMOS INPUT.
**INTERNAL 5k⍀ PULL-DOWN RESISTOR ON EACH RS-232 INPUT.
5V INPUT
VCC
T1IN
T1OUT
T1
RS-232
OUTPUTS
TTL/CMOS
INPUTS*
T2IN
T2OUT
T2
R1OUT
R1
R1IN
R2OUT
R2
R2IN
RS-232
INPUTS**
TTL/CMOS
OUTPUTS
DO NOT MAKE
CONNECTIONS
TO THESE PINS
C1+
C2+
C1–
C2+
INTERNAL
–10V POWER
SUPPLY
INTERNAL
+10V POWER
SUPPLY
V–
C2–
V–
ADM203
C2–
V+
GND
GND
*INTERNAL 400k⍀ PULL-UP RESISTOR ON EACH TTL/CMOS INPUT.
**INTERNAL 5k⍀ PULL-DOWN RESISTOR ON EACH RS-232 INPUT.
REV. A
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2001
