Analog Devices ADM202E, ADM1181A Datasheet
EMI/EMC Compliant, 615 kV ESD Protected,
C1+
C1–
C2+
C2–
V
CC
0.1µF
10V
0.1µF
10V
V+
V–
+5V TO +10V
VOLTAGE
DOUBLER
3
1
2
+5V INPUT
C3
0.1µF
10V
4
5
+10V TO –10V
VOLTAGE
INVERTER
6
C4
0.1µF
10V
14
11
T1
OUT
T1
IN
16
C5
0.1µF
10V
7
10
T2
OUT
T2
IN
12
13
8
9
ADM1181A
R1
OUT
R2
OUT
R1
IN
R2
IN
CMOS
INPUTS
CMOS
OUTPUTS
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS
*
15
NOTE
*
INTERNAL 5kΩ PULL-DOWN RESISTOR ON EACH RS-232 INPUT
GND
C1+
C1–
C2+
C2–
V
CC
0.1µF
10V
0.1µF
10V
V+
V–
+5V TO +10V
VOLTAGE
DOUBLER
3
1
2
+5V INPUT
C3
0.1µF
6.3V
4
5
+10V TO –10V
VOLTAGE
INVERTER
6
C4
0.1µF
10V
14
11
T1
OUT
T1
IN
16
C5
0.1µF
7
10
T2
OUT
T2
IN
12
13
8
9
ADM202E
R1
OUT
R2
OUT
R1
IN
R2
IN
CMOS
INPUTS
CMOS
OUTPUTS
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS
*
15
NOTE
*
INTERNAL 5kΩ PULL-DOWN RESISTOR ON EACH RS-232 INPUT
GND
T1
T2
R1
R2
T1
T2
R1
R2
a
FEATURES
Complies with 89/336/EEC EMC Directive
ESD Protection to IEC1000-4-2 (801.2)
68 kV: Contact Discharge
615 kV: Air-Gap Discharge
615 kV: Human Body Model
EFT Fast Transient Burst Immunity (IEC1000-4-4)
Low EMI Emissions (EN55022)
230 kbits/s Data Rate Guaranteed
TSSOP Package Option
Upgrade for MAX202E, 232E, LT1181A
APPLICATIONS
General Purpose RS-232 Data Link
Portable Instruments
PDAs
GENERAL DESCRIPTION
The ADM202E and ADM1181A are robust, high speed, 2channel RS232/V.28 interface devices that operate from a single
+5 V power supply. Both products are suitable for operation in
harsh electrical environments and are compliant with the EU directive on EMC (89/336/EEC). Both the level of electromagnetic emissions and immunity are in compliance. EM immunity
includes ESD protection in excess of ± 15 kV on all I/O lines,
Fast Transient burst protection (1000-4-4) and Radiated Immunity (1000-4-3). EM emissions include radiated and
conducted emissions as required by Information Technology
Equipment EN55022, CISPR22.
The ADM202E and ADM1181A conform to the EIA-232E and
CCITT V.28 specifications and operate at data rates up to
230 kbps.
Four external 0.1 µF charge pump capacitors are used for the
voltage doubler/inverter permitting operation from a single +5 V
supply.
The ADM202E provides a robust pin-compatible upgrade for
existing ADM202, ADM232L or MAX202E/MAX232E sockets. It is available in a 16-pin DIP, wide and narrow SO and also
a space saving TSSOP package. The TSSOP package gives a
44% space saving over SOIC.
The ADM1181A provides a robust pin compatible upgrade for
the LTC1181A, and it is available in 16-pin DIP and 16-lead
SO packages.
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.
RS-232 Line Drivers/Receivers
ADM202E/ADM1181A
FUNCTIONAL BLOCK DIAGRAMS
ORDERING GUIDE
Model Temperature Range Package Option
ADM202EAN –40°C to +85°C N-16
ADM202EARW –40°C to +85°C R-16W
ADM202EARN –40°C to +85°C R-16N
ADM202EARU –40°C to +85°C RU-16
ADM1181AAN –40°C to +85°C N-16
ADM1181AARW –40°C to +85°C R-16W
© Analog Devices, Inc., 1996
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 617/329-4700 Fax: 617/326-8703
(VCC = +5.0 V 6 10%, C1–C4 = 0.1 mF. All specifications
ADM202E/ADM1181A–SPECIFICA TIONS
T
to T
MIN
unless otherwise noted.)
MAX
Parameter Min Typ Max Units Test Conditions/Comments
DC CHARACTERISTICS
Operating Voltage Range 4.5 5.0 5.5 Volts
V
Power Supply Current 2.0 3.0 mA No Load
CC
15 18 mA RL = 3 kΩ to GND
LOGIC
Input Logic Threshold Low, V
Input Logic Threshold High, V
CMOS Output Voltage Low, V
CMOS Output Voltage High, V
INL
INH
OL
OH
2.4 V T
3.5 V I
Input Leakage Current 0.01 ±10 µAT
0.8 V T
0.4 V I
IN
IN
= 3.2 mA
OUT
= –1 mA
OUT
= GND to V
IN
CC
RS-232 RECEIVER
EIA-232 Input Voltage Range –30 +30 V
EIA-232 Input Threshold Low 0.4 0.8 V
EIA-232 Input Threshold High 1.1 2.4 V
EIA-232 Input Hysteresis 0.7 V
EIA-232 Input Resistance 3 5 7 kΩ
RS-232 TRANSMITTER
Output Voltage Swing ±5.0 ±9.0 Volts All Transmitter Outputs
Loaded with 3 kΩ to Ground
Transmitter Output Resistance 300 Ω V
= 0 V, V
CC
OUT
= ±2 V
RS-232 Output Short Circuit Current ±15 ±60 mA
TIMING CHARACTERISTICS
Maximum Data Rate 230 kbps R
= 3 kΩ to 7 kΩ, CL = 50 pF to 2500 pF
L
Receiver Propagation Delay
TPHL 0.3 1 µs
TPLH 0.6 1 µs
Transmitter Propagation Delay 1.2 1.5 µsR
Transition Region Slew Rate 3 10 30 V/µsR
= 3 kΩ, CL = 2500 pF
L
= 3 kΩ, CL = 2500 pF
L
Measured from +3 V to –3 V or
–3 V to +3 V
EM IMMUNITTY
ESD Protection (I/O pins) ±15 kV Human Body Model
±15 kV IEC1000-4-2 Air Discharge
±8 kV kV IEC1000-4-2 Contact Discharge
EFT Protection (I/O pins) ±2 kV IEC1000-4-4
EMI Immunity 10 V/m IEC1000-4-3
Specifications subject to change without notice.
ABSOLUTE MAXIMUM RATINGS*
(TA = +25°C unless otherwise noted)
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–0.3 V to +6 V
V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . (V
– 0.3 V) to +14 V
CC
V– . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+0.3 V to –14 V
Input Voltages
T
. . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to (V+, +0.3 V)
IN
R
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±30 V
IN
Output Voltages
T
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±15 V
OUT
R
. . . . . . . . . . . . . . . . . . . . . . . .–0.3 V to (VCC + 0.3 V)
OUT
Short Circuit Duration
T
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
OUT
Power Dissipation
Power Dissipation N-16 . . . . . . . . . . . . . . . . . . . . . . . .450 mW
(Derate 6 mW/°C above +50°C)
θ
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 117°C/W
JA
Power Dissipation R-16 . . . . . . . . . . . . . . . . . . . . . . . .450 mW
(Derate 6 mW/°C above +50°C)
θ
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 158°C/W
JA
Power Dissipation RU-16 . . . . . . . . . . . . . . . . . . . . . .500 mW
(Derate 6 mW/°C above +50°C)
θ
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 158°C/W
JA
Operating Temperature Range
Industrial (A Version) . . . . . . . . . . . . . . . . .–40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . .–65°C to +150°C
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . +300°C
ESD Rating (MIL-STD-883B) (I/O Pins) . . . . . . . . . . ±15 kV
ESD Rating MIL-STD-883B (Except I/O) . . . . . . . . . . ±3 kV
ESD Rating (IEC1000-4-2 Air) (I/O Pins) . . . . . . . . . ±15 kV
ESD Rating (IEC1000-4-2 Contact) (I/O Pins) . . . . . . . ±8 kV
EFT Rating (IEC1000-4-4) (I/O Pins) . . . . . . . . . . . . . ±2 kV
*This is a stress rating only and functional operation of the device at these or any
other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended
periods of time may affect reliability.
–2–
REV. 0
ADM202E/ADM1181A
C1+
C1–
C2+
C2–
V
CC
0.1µF
10V
0.1µF
10V
V+
V–
+5V TO +10V
VOLTAGE
DOUBLER
3
1
2
+5V INPUT
C3
0.1µF
10V
4
5
+10V TO –10V
VOLTAGE
INVERTER
6
C4
0.1µF
10V
T1
14
11
T1
OUT
T1
IN
16
C5
0.1µF
10V
7
10
T2
OUT
T2
IN
T2
12
13
8
9
R1
R2
ADM1181A
R1
OUT
R2
OUT
R1
IN
R2
IN
CMOS
INPUTS
CMOS
OUTPUTS
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS
*
15
NOTE
*
INTERNAL 5kΩ PULL-DOWN RESISTOR ON EACH RS-232 INPUT
GND
14
13
12
11
16
15
10
9
8
1
2
3
4
7
6
5
TOP VIEW
(Not to Scale)
ADM202E
ADM1181A
NC = NO CONNECT
C1+
R1
IN
T1
OUT
GND
V
CC
V+
C1–
C2+
T2
IN
T1
IN
R1
OUT
C2–
V–
T2
OUT
R2
IN
R2
OUT
PIN FUNCTION DESCRIPTION
Mnemonic Function
V
CC
Power Supply Input: +5 V ± 10%.
V+ Internally Generated Positive Supply
(+9 V nominal).
V– Internally Generated Negative Supply
(–9 V nominal).
GND Ground Pin. Must Be Connected to 0 V.
C1+, C1– External Capacitor 1 is connected between
these pins. 0.1 µF capacitor is recommended
but larger capacitors up to 47 µF may be used.
C2+, C2– External Capacitor 2 is connected between
these pins. 0.1 µF capacitor is recommended
but larger capacitors up to 47 µF may be used.
T
IN
Transmitter (Driver) Inputs. These inputs ac-
cept TTL/CMOS levels.
T
OUT
Transmitter (Driver) Outputs. These are RS-
232 signal levels (typically ±9 V).
R
IN
Receiver Inputs. These inputs accept RS-232
signal levels. An Internal 5 kΩ pull-down resis-
tor to GND is connected on each input.
R
OUT
Receiver Outputs. These are CMOS output
logic levels.
PIN CONNECTIONS
1
C1+
3
C1–
4
C2+
5
C2–
11
IN
10
IN
12
9
CMOS
INPUTS
CMOS
OUTPUTS
NOTE
0.1µF
10V
0.1µF
10V
R1
R2
T1
T2
OUT
OUT
*INTERNAL 5kΩ PULL-DOWN RESISTOR ON EACH RS-232 INPUT
REV. 0
ADM202E Typical Operating Circuit
+5V TO +10V
VOLTAGE
DOUBLER
+10V TO –10V
VOLTAGE
INVERTER
T1
T2
R1
R2
GND
15
ADM202E
+5V INPUT
16
V
CC
2
V+
6
V–
14
7
13
8
C4
0.1µF
10V
T1
T2
R1
R2
C3
0.1µF
6.3V
OUT
OUT
IN
IN
C5
0.1µF
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS
*
ADM1181A Typical Operating Circuit
–3–
ADM202E/ADM1181A
S1
S2
C1
S4
S3
C3
V+ = 2V
CC
V
CC
V
CC
GND
INTERNAL
OSCILLATOR
NOTE: C3 CONNECTS BETWEEN V+ AND GND ON THE ADM1181A
GENERAL DESCRIPTION
The ADM202E/ADM1181E are ruggedized RS-232 line drivers/
receivers. Step-up voltage converters coupled with level shifting
transmitters and receivers allow RS-232 levels to be developed
while operating from a single +5 V supply.
Features include low power consumption, high transmission
rates and compatibility with the EU directive on Electromagnetic compatibility. EM compatibility includes protection
against radiated and conducted interference including high
levels of Electrostatic Discharge.
All inputs and outputs contain protection against Electrostatic
Discharges up to ±15 kV and Electrical Fast Transients up to
±2 kV. This ensures compliance to IE1000-4-2 and IEC1000-4-4
requirements.
The devices are ideally suited for operation in electrically harsh
environments or where RS-232 cables are frequently being
plugged/unplugged. They are also immune to high RF field
strengths without special shielding precautions.
CMOS technology is used to keep the power dissipation to an
absolute minimum allowing maximum battery life in portable
applications.
The ADM202E/ADM1181A is a modification, enhancement
and improvement to the AD230–AD241 family and its derivatives. It is essentially plug-in compatible and does not have materially different applications.
CIRCUIT DESCRIPTION
The internal circuitry consists of four main sections. These are:
1. A charge pump voltage converter
2. 5 V logic to EIA-232 transmitters
3. EIA-232 to 5 V logic receivers.
4. Transient protection circuit on all I/O lines
Charge Pump DC-DC Voltage Converter
The charge pump voltage converter consists of an 200 kHz oscillator and a switching matrix. The converter generates a ±10 V
supply from the input +5 V level. This is done in two stages using a switched capacitor technique as illustrated below. First,
the 5 V input supply is doubled to 10 V using capacitor C1 as
the charge storage element. The 10 V level is then inverted to
generate –10 V using C2 as the storage element.
Capacitors C3 and C4 are used to reduce the output ripple.
Their values are not critical and can be increased if desired. On
the ADM202E, capacitor C3 is shown connected between V+
and V
, while it is connected between V+ and GND on the
CC
ADM1181A. It is acceptable to use either configuration with
both the ADM202E and ADM1181A. If desired, larger capacitors (up to 47 µF) can be used for capacitors C1–C4. This facili-
tates direct substitution with older generation charge pump
RS-232 transceivers.
Figure 1. Charge Pump Voltage Doubler
FROM
VOLTAGE
DOUBLER
V+
GND
INTERNAL
OSCILLATOR
S1
S2
C2
S3
S4
C4
GND
V– = –(V+)
Figure 2. Charge Pump Voltage Inverter
Transmitter (Driver) Section
The drivers convert 5 V logic input levels into RS-232 output
levels. With V
= +5 V and driving an RS-232 load, the output
CC
voltage swing is typically ± 9 V.
Receiver Section
The receivers are inverting level shifters which accept RS-232
input levels and translate them into 5 V logic output levels.
The inputs have internal 5 kΩ pull-down resistors to ground
and are also protected against overvoltages of up to ± 30 V. Unconnected inputs are pulled to 0 V by the internal 5 kΩ pulldown resistor. This, therefore, results in a Logic 1 output level
for unconnected inputs or for inputs connected to GND.
The receivers have Schmitt trigger inputs with a hysteresis level
of 0.5 V. This ensures error-free reception for both noisy inputs
and for inputs with slow transition times.
–4–
REV. 0
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