High-Speed, 5 V, 0.1 F
CMOS RS-232 Driver/Receivers
a
ADM202/ADM203
FEATURES
FUNCTIONAL BLOCK DIAGRAMS
120 kB Transmission Rate
5V INPUT
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
0.1F
V
C1+
C1–
CC
+5V TO +10V
VOLTAGE
DOUBLER
6.3V
0.1F
6.3V
0.1F
6.3V
V+
V–
C2+
C2–
+10V TO –10V
VOLTAGE
INVERTER
0.1F
16V
0.1F
16V
T1
IN
T1
T1
T2
R1
R2
OUT
TTL/CMOS
INPUTS*
RS-232
APPLICATIONS
Computers
Peripherals
Modems
Printers
Instruments
OUTPUTS
T2
IN
T2
OUT
R1
R1
IN
OUT
TTL/CMOS
OUTPUTS
RS-232
INPUTS**
R2
R2
IN
OUT
GND
ADM202
*INTERNAL 400k⍀ PULL-UP RESISTOR ON EACH TTL/CMOS INPUT.
**INTERNAL 5k⍀ PULL-DOWN RESISTOR ON EACH RS-232 INPUT.
GENERAL DESCRIPTION
5V INPUT
The ADM202/ADM203 is a two-channel RS-232 line driver/
receiver pair designed to operate from a single 5 V power sup-
ply. 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.
V
CC
T1
T2
T1
T2
T1
T2
IN
OUT
TTL/CMOS
INPUTS*
RS-232
OUTPUTS
IN
OUT
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.
R1
R1
R2
R1
R2
OUT
OUT
IN
TTL/CMOS
OUTPUTS
RS-232
INPUTS**
R2
IN
An epitaxial BiCMOS construction minimizes power consump-
tion 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.
C1+
C1–
V–
DO NOT MAKE
CONNECTIONS
TO THESE PINS
C2+
C2+
C2–
C2–
INTERNAL
–10V POWER
SUPPLY
V–
ADM203
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.
INTERNAL
+10V POWER
SUPPLY
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.
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© Analog Devices, Inc., 2001