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Электронный компонент: ADM1181AARW

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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.
a
EMI/EMC Compliant, 15 kV ESD Protected,
RS-232 Line Drivers/Receivers
ADM202E/ADM1181A
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
FUNCTIONAL BLOCK DIAGRAMS
C1+
C1
C2+
C2
V
CC
0.1F
10V
0.1F
10V
V+
V
+5V TO +10V
VOLTAGE
DOUBLER
3
1
2
+5V INPUT
C3
0.1F
10V
4
5
+10V TO 10V
VOLTAGE
INVERTER
6
C4
0.1F
10V
14
11
T1
OUT
T1
IN
16
C5
0.1F
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 5k
PULL-DOWN RESISTOR ON EACH RS-232 INPUT
GND
C1+
C1
C2+
C2
V
CC
0.1F
10V
0.1F
10V
V+
V
+5V TO +10V
VOLTAGE
DOUBLER
3
1
2
+5V INPUT
C3
0.1F
6.3V
4
5
+10V TO 10V
VOLTAGE
INVERTER
6
C4
0.1F
10V
14
11
T1
OUT
T1
IN
16
C5
0.1F
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 5k
PULL-DOWN RESISTOR ON EACH RS-232 INPUT
GND
T1
T2
R1
R2
T1
T2
R1
R2
GENERAL DESCRIPTION
The ADM202E and ADM1181A are robust, high speed, 2-
channel 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 di-
rective on EMC (89/336/EEC). Both the level of electromag-
netic 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 Im-
munity (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
F 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 sock-
ets. 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.
FEATURES
Complies with 89/336/EEC EMC Directive
ESD Protection to IEC1000-4-2 (801.2)
8 kV: Contact Discharge
15 kV: Air-Gap Discharge
15 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
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
REV. 0
2
ADM202E/ADM1181ASPECIFICATIONS
(V
CC
= +5.0 V
10%, C1C4 = 0.1 F. All specifications
T
MIN
to T
MAX
unless otherwise noted.)
Parameter
Min
Typ
Max
Units
Test Conditions/Comments
DC CHARACTERISTICS
Operating Voltage Range
4.5
5.0
5.5
Volts
V
CC
Power Supply Current
2.0
3.0
mA
No Load
15
18
mA
R
L
= 3 k
to GND
LOGIC
Input Logic Threshold Low, V
INL
0.8
V
T
IN
Input Logic Threshold High, V
INH
2.4
V
T
IN
CMOS Output Voltage Low, V
OL
0.4
V
I
OUT
= 3.2 mA
CMOS Output Voltage High, V
OH
3.5
V
I
OUT
= 1 mA
Input Leakage Current
0.01
10
A
T
IN
= GND to V
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
k
RS-232 TRANSMITTER
Output Voltage Swing
5.0
9.0
Volts
All Transmitter Outputs
Loaded with 3 k
to Ground
Transmitter Output Resistance
300
V
CC
= 0 V, V
OUT
=
2 V
RS-232 Output Short Circuit Current
15
60
mA
TIMING CHARACTERISTICS
Maximum Data Rate
230
kbps
R
L
= 3 k
to 7 k
, C
L
= 50 pF to 2500 pF
Receiver Propagation Delay
TPHL
0.3
1
s
TPLH
0.6
1
s
Transmitter Propagation Delay
1.2
1.5
s
R
L
= 3 k
, C
L
= 2500 pF
Transition Region Slew Rate
3
10
30
V/
s
R
L
= 3 k
, C
L
= 2500 pF
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*
(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 +50
C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 117
C/W
Power Dissipation R-16 . . . . . . . . . . . . . . . . . . . . . . . . 450 mW
(Derate 6 mW/
C above +50
C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 158
C/W
Power Dissipation RU-16 . . . . . . . . . . . . . . . . . . . . . . 500 mW
(Derate 6 mW/
C above +50
C)
JA
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 158
C/W
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 specifica-
tion is not implied. Exposure to absolute maximum rating conditions for extended
periods of time may affect reliability.
ADM202E/ADM1181A
3
REV. 0
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
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.
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 k
pull-down resis-
tor to GND is connected on each input.
R
OUT
Receiver Outputs. These are CMOS output
logic levels.
C1+
C1
C2+
C2
V
CC
0.1F
10V
0.1F
10V
V+
V
+5V TO +10V
VOLTAGE
DOUBLER
3
1
2
+5V INPUT
C3
0.1F
6.3V
4
5
+10V TO 10V
VOLTAGE
INVERTER
6
C4
0.1F
10V
T1
14
11
T1
OUT
T1
IN
16
C5
0.1F
7
10
T2
OUT
T2
IN
T2
12
13
8
9
R1
R2
ADM202E
R1
OUT
R2
OUT
R1
IN
R2
IN
CMOS
INPUTS
CMOS
OUTPUTS
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS
*
15
NOTE
*
INTERNAL 5k
PULL-DOWN RESISTOR ON EACH RS-232 INPUT
GND
ADM202E Typical Operating Circuit
C1+
C1
C2+
C2
V
CC
0.1F
10V
0.1F
10V
V+
V
+5V TO +10V
VOLTAGE
DOUBLER
3
1
2
+5V INPUT
C3
0.1F
10V
4
5
+10V TO 10V
VOLTAGE
INVERTER
6
C4
0.1F
10V
T1
14
11
T1
OUT
T1
IN
16
C5
0.1F
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 5k
PULL-DOWN RESISTOR ON EACH RS-232 INPUT
GND
ADM1181A Typical Operating Circuit
PIN CONNECTIONS
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
ADM202E/ADM1181A
4
REV. 0
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 Electromag-
netic 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 AD230AD241 family and its deriva-
tives. It is essentially plug-in compatible and does not have ma-
terially 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 os-
cillator and a switching matrix. The converter generates a
10 V
supply from the input +5 V level. This is done in two stages us-
ing 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
CC
, while it is connected between V+ and GND on the
ADM1181A. It is acceptable to use either configuration with
both the ADM202E and ADM1181A. If desired, larger capaci-
tors (up to 47
F) can be used for capacitors C1C4. This facili-
tates direct substitution with older generation charge pump
RS-232 transceivers.
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
Figure 1. Charge Pump Voltage Doubler
S1
S2
C2
S4
S3
C4
V = (V+)
V+
GND
INTERNAL
OSCILLATOR
GND
FROM
VOLTAGE
DOUBLER
Figure 2. Charge Pump Voltage Inverter
Transmitter (Driver) Section
The drivers convert 5 V logic input levels into RS-232 output
levels. With V
CC
= +5 V and driving an RS-232 load, the output
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 k
pull-down resistors to ground
and are also protected against overvoltages of up to
30 V. Un-
connected inputs are pulled to 0 V by the internal 5 k
pull-
down 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.
ADM202E/ADM1181A
5
REV. 0
HIGH BAUD RATE
The ADM202E/ADM1181A feature high slew rates permitting
data transmission at rates well in excess of the EIA/RS-232-E
specifications. RS-232 voltage levels are maintained at data rates
up to 230 kb/s even under worst case loading conditions. This
allows for high speed data links between two terminals or indeed
it is suitable for the new generation I
SDN
modem standards which
requires data rates of 230 kbps. The slew rate is internally con-
trolled to less than 30 V/
s in order to minimize EMI interference.
ESD/EFT TRANSIENT PROTECTION SCHEME.
The ADM202E/ADM1181A use protective clamping structures
on all inputs and outputs which clamp the voltage to a safe level
and dissipate the energy present in ESD (Electrostatic) and
EFT (Electrical Fast Transients) discharges. A simplified sche-
matic of the protection structure is shown in Figure 3. Each in-
put and output contains two back-to-back high speed clamping
diodes. During normal operation with maximum RS-232 signal
levels, the diodes have no effect as one or the other is reverse bi-
ased depending on the polarity of the signal. If however the volt-
age exceeds about 50 V in either direction, reverse breakdown
occurs and the voltage is clamped at this level. The diodes are
large p-n junctions that are designed to handle the instanta-
neous current surge which can exceed several amperes.
The transmitter outputs and receiver inputs have a similar pro-
tection structure. The receiver inputs can also dissipate some of
the energy through the internal 5 k
resistor to GND as well as
through the protection diodes.
The protection structure achieves ESD protection up to
15 kV
and EFT protection up to
2 kV on all RS-232 I/O lines. The
methods used to test the protection scheme are discussed later.
R
IN
RX
D1
D2
RECEIVER
INPUT
R1
Figure 3a. Receiver Input Protection Scheme
RX
D1
D2
TRANSMITTER
OUTPUT
T
OUT
Figure 3b. Transmitter Output Protection Scheme
Typical Performance Curves
START 30.0 MHz
STOP 200.0 MHz
LIMIT
dBV
80
70
60
50
40
30
20
10
0
Figure 4. EMC Radiated Emissions
LOG FREQUENCY MHz
80
70
0
0.3
30
0.6
1
60
50
10
40
30
20
3
6
10
dBV
LIMIT
Figure 5. EMC Conducted Emissions