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.
a
ADM3202/ADM3222/ADM1385
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
Low Power, +3.3 V, RS-232
Line Drivers/Receivers
FUNCTIONAL BLOCK DIAGRAMS
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
GENERAL DESCRIPTION
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
F 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
A. 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.
+3.3V TO +6.6V
VOLTAGE
DOUBLER
C1+
C1
C5
0.1 F
+
V
CC
V+
0.1 F
10V
+
+
C3
0.1 F
6.3V
+3.3V INPUT
+6.6V TO 6.6V
VOLTAGE
INVERTER
C2+
C2
+
V
0.1 F
10V
+
C4
0.1 F
10V
T1
OUT
T1
IN
T2
OUT
T2
IN
EIA/TIA-232
OUTPUTS
R1
OUT
R2
OUT
R1
IN
R2
IN
EIA/TIA-232
INPUTS*
CMOS
INPUTS
CMOS
OUTPUTS
ADM3202
GND
*INTERNAL 5k PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
+3.3V TO +6.6V
VOLTAGE
DOUBLER
C1+
C1
C5
0.1 F
+
V
CC
V+
0.1 F
10V
+
+
C3
0.1 F
6.3V
+3.3V INPUT
+6.6V TO 6.6V
VOLTAGE
INVERTER
C2+
C2
+
V
0.1 F
10V
+
C4
0.1 F
10V
T1
OUT
T1
IN
T2
OUT
T2
IN
EIA/TIA-232
OUTPUTS
R1
OUT
R2
OUT
R1
IN
R2
IN
EIA/TIA-232
INPUTS*
CMOS
INPUTS
CMOS
OUTPUTS
ADM3222
GND
*INTERNAL 5k PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
T1
T2
R2
R1
T1
T2
R2
R1
EN
SD
+3.3V TO +6.6V
VOLTAGE
DOUBLER
C1+
C1
C5
0.1 F
+
V
CC
V+
0.1 F
10V
+
C3
0.1 F
6.3V
+3.3V INPUT
+6.6V TO 6.6V
VOLTAGE
INVERTER
C2+
C2
+
V
0.1 F
10V
+
C4
0.1 F
10V
T1
OUT
T1
IN
T2
OUT
T2
IN
EIA/TIA-232
OUTPUTS
R1
OUT
R2
OUT
R1
IN
R2
IN
EIA/TIA-232
INPUTS*
CMOS
INPUTS
CMOS
OUTPUTS
ADM1385
GND
*INTERNAL 5k PULL-DOWN RESISTOR
ON EACH RS-232 INPUT
T1
T2
R2
R1
DD
SD
+
2
REV. A
ADM3202/ADM3222/ADM1385SPECIFICATIONS
Parameter
Min
Typ
Max
Unit
Test Conditions/Comments
DC CHARACTERISTICS
Operating Voltage Range
3.0
3.3
5.5
V
V
CC
Power Supply Current
1.3
2.1
mA
No Load
8
10
mA
R
L
= 3 k
to GND
Shutdown Supply Current
0.01
0.5
A
LOGIC
Input Logic Threshold Low, V
INL
0.8
V
T
IN
Input Logic Threshold High, V
INH
2.0
V
T
IN
CMOS Output Voltage Low, V
OL
0.4
V
I
OUT
= 1.6 mA
CMOS Output Voltage High, V
OH
V
CC
0.6
V
I
OUT
= 1 mA
Input Leakage Current
0.01
1
A
T
IN
= GND to V
CC
*
Output Leakage Current
10
A
Receivers Disabled
RS-232 RECEIVER
EIA-232 Input Voltage Range
30
+30
V
EIA-232 Input Threshold Low
0.6
1.2
V
EIA-232 Input Threshold High
1.6
2.4
V
EIA-232 Input Hysteresis
0.4
V
EIA-232 Input Resistance
3
5
7
k
RS-232 TRANSMITTER
Output Voltage Swing (RS-232)
5.0
5.2
V
V
CC
= 3.3 V. All Transmitter Outputs Loaded
with 3 k
to Ground
Output Voltage Swing (RS-562)
3.7
V
V
CC
= 3.0 V
Transmitter Output Resistance
300
V
CC
= 0 V, V
OUT
=
2 V
RS-232 Output Short Circuit Current
15
mA
Output Leakage Current
25
A
SD = Low, V
OUT
= 12 V
TIMING CHARACTERISTICS
Maximum Data Rate
460
kbps
V
CC
= 3.3 V, R
L
= 3 k
to 7 k, C
L
= 50 pF to
Receiver Propagation Delay
1000 pF. One Tx Switching
TPHL
0.4
1
s
TPLH
0.4
1
s
Transmitter Propagation Delay
300
750
ns
R
L
= 3 k
, C
L
= 1000 pF
Receiver Output Enable Time
200
ns
Receiver Output Disable Time
200
ns
Transmitter Skew
30
ns
Receiver Skew
300
ns
Transition Region Slew Rate
Measured from +3 V to 3 V or 3 V to +3 V,
V
CC
= +3.3 V
6
10
30
V/
s
R
L
= 3 k
, C
L
= 1000 pF, T
A
= +25
C
4
10
30
V/
s
R
L
= 3 k
, C
L
= 2500 pF, T
A
= +25
C
*ADM1385: Input leakage current typically 10
A when T
IN
= GND.
Specifications subject to change without notice.
(V
CC
= +3.3 V
0.3 V, C1C4 = 0.1 F. All specifications T
MIN
to T
MAX
unless otherwise noted.)
ADM3202/ADM3222/ADM1385
3
REV. A
ABSOLUTE MAXIMUM RATINGS
*
(T
A
= +25
C unless otherwise noted)
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to +6 V
V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . (V
CC
0.3 V) to +14 V
V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +0.3 V to 14 V
Input Voltages
T
IN
. . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to (V+, +0.3 V)
R
IN
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30 V
Output Voltages
T
OUT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15 V
R
OUT
. . . . . . . . . . . . . . . . . . . . . . . 0.3 V to (V
CC
+ 0.3 V)
Short Circuit Duration
T
OUT
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
Power Dissipation
Power Dissipation N-16 . . . . . . . . . . . . . . . . . . . . . 450 mW
(Derate 6 mW/
C above +50C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . 117
C/W
Power Dissipation R-16 . . . . . . . . . . . . . . . . . . . . . 450 mW
(Derate 6 mW/
C above +50C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . 158
C/W
Power Dissipation RU-16 . . . . . . . . . . . . . . . . . . . 500 mW
(Derate 6 mW/
C above +50C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . 158
C/W
Power Dissipation R-18 . . . . . . . . . . . . . . . . . . . . . 450 mW
(Derate 6 mW/
C above +50C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . 158
C/W
Power Dissipation RS-20 . . . . . . . . . . . . . . . . . . . . 450 mW
(Derate 6 mW/
C above +50C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . 158
C/W
Power Dissipation RU-20 . . . . . . . . . . . . . . . . . . . 450 mW
(Derate 6 mW/
C above +50C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . 158
C/W
Operating Temperature Range
Industrial (A Version) . . . . . . . . . . . . . . . . 40
C to +85C
Storage Temperature Range . . . . . . . . . . . . 65
C to +150C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . +300
C
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .<1500 V
*This is a stress rating only; functional operation of the device at these or any other
conditions above those indicated in the operation sections of this specificatio n
is not implied. Exposure to absolute maximum rating conditions for extended
periods of time may affect reliability.
ORDERING GUIDE
Model
Temperature Range
Package Options
*
ADM3202AN
40
C to +85C
N-16
ADM3202ARN
40
C to +85C
R-16A
ADM3202ARW
40
C to +85C
R-16
ADM3202ARU
40
C to +85C
RU-16
ADM3222AN
40
C to +85C
N-18
ADM3222ARW
40
C to +85C
R-18
ADM3222ARS
40
C to +85C
RS-20
ADM3222ARU
40
C to +85C
RU-20
ADM1385ARS
40
C to +85C
RS-20
*N = Plastic DIP; R = Small Outline; RS = Shrink Small Outline; RU = Thin
Shrink Small Outline.
ADM3202/ADM3222/ADM1385
4
REV. A
PIN FUNCTION DESCRIPTIONS
Mnemonic
Function
V
CC
Power Supply Input: +3.3 V
0.3 V.
V+
Internally Generated Positive Supply
(+6 V Nominal).
V
Internally Generated Negative Supply
(6 V Nominal).
GND
Ground Pin. Must be connected to 0 V.
C1+, C1
External Capacitor 1 is connected between these
pins. 0.1
F capacitor is recommended but larger
capacitors up to 47
F may be used.
C2+, C2
External Capacitor 2 is connected between these
pins. 0.1
F capacitor is recommended but larger
capacitors up to 47
F may be used.
Tx
IN
Transmitter (Driver) Inputs. These inputs accept
TTL/CMOS levels.
Tx
OUT
Transmitter (Driver) Outputs. These are RS-232
signal levels (typically
9 V).
Rx
IN
Receiver Inputs. These inputs accept RS-232
signal levels. An internal 5 k
pull-down resistor
to GND is connected on each input.
Rx
OUT
Receiver Outputs. These are CMOS output logic
levels.
EN
(ADM3222) Receiver Enable, Active Low. When
low, the receiver outputs are enabled. When high,
they are three-stated.
SD
(ADM3222) Shutdown Control. Active Low.
When low, the charge pump is shut down and
the transmitter outputs are disabled.
SD
(ADM1385) Shutdown Control. When low, the
charge pump is shut down and all transmitters
and receivers are disabled.
DD
(ADM1385) Driver Disable. When low, the
charge pump is turned off and the transmitters
are disabled. The receivers remain active.
PIN CONNECTIONS DIP (N, R Packages)
PIN CONNECTIONS DIP (RS, RU Packages)
TOP VIEW
(Not to Scale)
20
19
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
9
10
ADM1385
(SSOP)
NC = NO CONNECT
NC
R2
IN
T2
OUT
C1+
V+
C1
V
C2
C2+
NC
T2
IN
T1
IN
V
CC
GND
T1
OUT
R2
OUT
R1
OUT
R1
IN
DD
SD
TOP VIEW
(Not to Scale)
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
C1+
V+
C1
C2+
C2
V
T2
OUT
R2
IN
V
CC
GND
T1
OUT
R1
IN
R1
OUT
T1
IN
T2
IN
R2
OUT
ADM3202
TOP VIEW
(Not to Scale)
20
19
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
9
10
ADM3222
(SSOP
TSSOP)
NC = NO CONNECT
R2
OUT
R2
IN
T2
OUT
C1+
V+
C1
V
C2
C2+
NC
T2
IN
T1
IN
V
CC
GND
T1
OUT
NC
R1
OUT
R1
IN
EN
SD
TOP VIEW
(Not to Scale)
18
17
16
15
14
13
12
11
10
1
2
3
4
5
6
7
8
9
ADM3222
R2
IN
T2
OUT
EN
C1+
V+
C1
V
C2
C2+
T2
IN
SD
V
CC
GND
T1
OUT
T1
IN
R1
OUT
R1
IN
R2
OUT
ADM3202/ADM3222/ADM1385
5
REV. A
Typical Performance Characteristics
LOAD CAPACITANCE pF
6
4
6
0
5000
1000
2000
3000
4000
2
0
2
4
T
OUT
(HIGH)
T
OUT
(LOW)
Figure 1. Transmitter Output Voltage High/Low vs. Load
Capacitance @ 230 kbps
V
CC
V
12
10
0
3
5.5
3.5
4.0
4.5
5.0
8
6
4
2
Figure 2. Transmitter Output Voltage High vs. V
CC
CURRENT mA
8
6
4
0
10
2
4
6
8
4
2
0
2
6
8
T1
OUT
(LOW) V
T1
OUT
(HIGH) V
Figure 3. Transmitter Output Voltage Low/High vs. Load
Current
CURRENT mA
8
6
4
0
10
20
30
40
4
2
0
2
6
8
V (V)
V+ (V)
Figure 4. Charge Pump V+, V vs. Current
V
CC
V
250
200
0
3.0
5.5
3.5
4.0
4.5
5.0
150
100
50
V IMPEDANCE
V+ IMPEDANCE
Figure 5. Charge Pump Impedance vs. V
CC
LOAD CAPACITANCE pF
25
20
0
0
5000
1000
2000
3000
4000
15
10
5
I
DD
(mA) @ 250kbps
I
DD
(mA) @ 160kbps
I
DD
(mA) @ 80kbps
Figure 6. Power Supply Current vs. Load Capacitance
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