a
FEATURES
460 kbps Data Rate
Specified at +3.3 V
Meets EIA-232E Specifications
0.1 F Charge Pump Capacitors
Low Power Shutdown (ADM3222E and ADM1385)
DIP, SO, SOIC, SSOP and TSSOP Package Options
Upgrade for MAX3222/32 and LTC1385
APPLICATIONS
General Purpose RS-232 Data Link
Portable Instruments
Printers
Palmtop Computers
PDAs
Low Power, +3.3 V, RS-232
Line Drivers/Receivers
ADM3202/ADM3222/ADM1385
FUNCTIONAL BLOCK DIAGRAMS
+3.3V INPUT
0.1 F
+
10V
C1+
+3.3V TO +6.6V
VOLTAGE
DOUBLER
C1–
C2+
+6.6V TO –6.6V
VOLTAGE
C2–
INVERTER
V
CC
V+
V–
C3
+
0.1 F
6.3V
C4
+
0.1 F
10V
+
C5
0.1 F
0.1 F
+
10V
T1
IN
CMOS
INPUTS
T1
T1
OUT
EIA/TIA-232
OUTPUTS
T2
IN
R1
OUT
CMOS
OUTPUTS
T2
T2
OUT
R1
IN
EIA/TIA-232
INPUTS*
R1
R2
OUT
R2
R2
IN
GND
ADM3202
*INTERNAL
5k PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
GENERAL DESCRIPTION
+3.3V INPUT
0.1 F
+
10V
The ADM3202/ADM3222/ADM1385 transceivers are high
speed, 2-channel RS-232/V.28 interface devices which operate
from a single +3.3 V power supply.
Low power consumption and a shutdown facility (ADM3222/
ADM1385) makes them ideal for battery powered portable
instruments.
The ADM3202/ADM3222/ADM1385 conforms to the EIA-
232E and CCITT V.28 specifications and operates at data rates
up to 460 kbps.
Four external 0.1
µF
charge pump capacitors are used for the
voltage doubler/inverter permitting operation from a single
+3.3 V supply.
The ADM3222 contains additional enable and shutdown cir-
cuitry. The
EN
input may be used to three-state the receiver
outputs. The
SD
input is used to power down the charge
pump and transmitter outputs reducing the quiescent current to
less than 0.5
µA.
The receivers remain enabled during shutdown
unless disabled using
EN.
The ADM1385 contains a driver disable mode and a complete
shutdown mode.
The ADM3202 is available in a 16-lead DIP, narrow and wide
SOIC as well as a space saving 20-lead TSSOP package. The
ADM3222 is available in 18-lead DIP, SO and in 20-lead SSOP
and TSSOP. The ADM1385 is available in a 20-lead SSOP
package, which is pin compatible with the LTC1385 CG.
CMOS
INPUTS
CMOS
INPUTS
C1+
+3.3V TO +6.6V
VOLTAGE
DOUBLER
C1–
C2+
+6.6V TO –6.6V
VOLTAGE
INVERTER
C2–
V
CC
V+
V–
C3
+
0.1 F
6.3V
C4
+
0.1 F
10V
+
C5
0.1 F
0.1 F
+
10V
T1
IN
T2
IN
R1
OUT
R2
OUT
EN
T1
T1
OUT
EIA/TIA-232
OUTPUTS
T2
T2
OUT
R1
IN
EIA/TIA-232
INPUTS*
R1
CMOS
OUTPUTS
R2
R2
IN
ADM3222
GND
SD
*INTERNAL
5k PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
+3.3V INPUT
0.1 F
+
10V
C1+
+3.3V TO +6.6V
VOLTAGE
C1–
DOUBLER
C2+
+6.6V TO –6.6V
VOLTAGE
C2–
INVERTER
V
CC
V+
+
V–
C4
+
0.1 F
10V
+
C5
0.1 F
C3
0.1 F
6.3V
0.1 F
+
10V
T1
IN
T2
IN
R1
OUT
R2
OUT
T1
T1
OUT
EIA/TIA-232
OUTPUTS
T2
T2
OUT
R1
IN
EIA/TIA-232
INPUTS*
R1
CMOS
OUTPUTS
R2
R2
IN
DD
ADM1385
GND
SD
*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., 2000
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