ADM202EAN ,EMI/EMC Compliant, +-15 kV ESD Protected, RS-232 Line Drivers/ReceiversGENERAL DESCRIPTIONNOTE*INTERNAL 5kΩ PULL-DOWN RESISTOR ON EACH RS-232 INPUTThe ADM202E and ADM1181 ..
ADM202EARN ,EMI/EMC Compliant, +-15 kV ESD Protected, RS-232 Line Drivers/ReceiversspecificationsCCADM202E/ADM1181A–
ADM202EARN-REEL7 , EMI/EMC-Compliant, -15 kV, ESD-Protected RS-232 Line Drivers/Receivers
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ADM202EARNZ-REEL , EMI/EMC-Compliant, -15 kV, ESD-Protected RS-232 Line Drivers/Receivers
ADM202EARU ,EMI/EMC Compliant, +-15 kV ESD Protected, RS-232 Line Drivers/ReceiversCHARACTERISTICSMaximum Data Rate 230 kbps R = 3 kΩ to 7 kΩ, C = 50 pF to 2500 pFL LReceiver Propaga ..
AH9249NTR-G1 , High Sensitivity Micropower Omnipolar Hall-Effect Switch
AHA4524A-031PTC , TURBO PRODUCT CODE ENCODER/DECODER
AHC138 , 3-LINE TO 8-LINE DECODERS/DEMULTIPLEXERS
AHC373 , OCTAL TRANSPARENT D-TYPE LATCHES WITH 3-STATE OUTPUTS
AHC573 , OCTAL TRANSPARENT D-TYPE LATCHES WITH 3-STATE OUTPUTS
AHC573 , OCTAL TRANSPARENT D-TYPE LATCHES WITH 3-STATE OUTPUTS
ADM1181AAN-ADM202EAN-ADM202EARN-ADM202EARU-ADM202EARW
EMI/EMC Compliant, +-15 kV ESD Protected, RS-232 Line Drivers/Receivers
REV.0
EMI/EMC Compliant, 615 kV ESD Protected,
GENERAL DESCRIPTIONThe 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 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 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)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
ORDERING GUIDE
ADM202E/ADM1181A–SPECIFICATIONS
(VCC = +5.0 V 6 10%, C1–C4 = 0.1 mF. All specifications
TMIN to TMAX unless otherwise noted.)Specifications subject to change without notice.
ABSOLUTE MAXIMUM RATINGS*(TA = +25°C unless otherwise noted)
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–0.3 V to +6 V . . . . . . . . . . . . . . . . . . . . . . . . . . . .(VCC – 0.3 V) to +14 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .+0.3 V to –14 V
Input Voltages
TIN . . . . . . . . . . . . . . . . . . . . . . . . . .–0.3 V to (V+, +0.3 V)
RIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±30 V
Output Voltages
TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .±15 V
ROUT . . . . . . . . . . . . . . . . . . . . . . . .–0.3 V to (VCC + 0.3 V)
Short Circuit Duration
TOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Continuous
Power Dissipation
Power Dissipation N-16 . . . . . . . . . . . . . . . . . . . . . . . .450 mW
(Derate 6 mW/°C above +50°C)
Power Dissipation R-16 . . . . . . . . . . . . . . . . . . . . . . . .450 mW
(Derate 6 mW/°C above +50°C)
θJA, Thermal Impedance . . . . . . . . . . . . . . . . . . . . .158°C/W
Power Dissipation RU-16 . . . . . . . . . . . . . . . . . . . . . .500 mW
(Derate 6 mW/°C above +50°C)
θJA, 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
PIN FUNCTION DESCRIPTION0.1µF
10V
0.1µF
10V
+5V INPUT
6.3VC4
0.1µF
10VT1OUTT1IN
0.1µFT2OUTT2IN
R1OUT
R2OUT
R1IN
R2IN
CMOS
INPUTS
CMOS
OUTPUTS
EIA/TIA-232
OUTPUTS
EIA/TIA-232
INPUTS*
NOTE
*INTERNAL 5kΩ PULL-DOWN RESISTOR ON EACH RS-232 INPUTADM202E Typical Operating Circuit
ADM1181A Typical Operating Circuit
PIN CONNECTIONS
ADM202E/ADM1181A
GENERAL DESCRIPTIONThe 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 AD230–AD241 family and its deriva-
tives. It is essentially plug-in compatible and does not have ma-
terially different applications.
CIRCUIT DESCRIPTIONThe internal circuitry consists of four main sections. These are:A charge pump voltage converter5V logic to EIA-232 transmittersEIA-232 to 5V logic receivers.
4. Transient protection circuit on all I/O lines
Charge Pump DC-DC Voltage ConverterThe 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 5V 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 VCC, 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 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
V– = –(V+)GND
GND
FROM
VOLTAGE
DOUBLERFigure 2.Charge Pump Voltage Inverter
Transmitter (Driver) SectionThe drivers convert 5V logic input levels into RS-232 output
levels. With VCC = +5V and driving an RS-232 load, the output
voltage swing is typically ±9 V.
Receiver SectionThe 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. Un-
connected inputs are pulled to 0 V by the internal 5 kΩ 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.
HIGH BAUD RATEThe 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 ISDN modem standards which
requires data rates of 230 kbps. The slew rate is internally con-
trolled to less than 30 V/μs 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 kΩ 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.
RECEIVER
INPUTFigure 3a.Receiver Input Protection Scheme
TRANSMITTER
OUTPUTFigure 3b.Transmitter Output Protection Scheme
Typical Performance Curves
START 30.0 MHzSTOP 200.0 MHz
LIMIT
dBµVFigure 4.EMC Radiated Emissions
Figure 5.EMC Conducted Emissions
ADM202E/ADM1181A
Typical Performance Curves
CL – pF02500500
OUT
VOLTAGE – V
100015002000Figure 6.Transmitter Output Voltage High/Low vs.
Load Capacitance @ 230 kbps
VCC – V5.53.5
OUT
– V+4.55Figure 7.Transmitter Output Voltage High vs. VCC
ILOAD – mA
CHARGE PUMP VOLTAGE152025
ILOAD – mA
OUT
– V345678
–10Figure 9.Transmitter Output Voltage Low/High vs.
Load Current
Figure 10.230 kbps Data Transmission
