UMW
R
ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
FEATURES
■ Meets true EIA/TIA-232-F Standards
from a +3.0V to +5.5V power supply
■ Minimum 120Kbps Data Rate Under Full
Load
■ 1µA Low-Power Shutdown with Receivers
Active (ADM3222A)
■ Enhanced ESD Specifications:
±15kV Human Body Model
±15kV IEC1000-4-2 Air Discharge
±8kV IEC1000-4-2 Contact Discharge
EN
18 SHDN
1
17 VCC
C1+ 2
V+
3
16 GND
C1-
4
15
T1OUT
C2+
5
14
R1IN
C2-
6
13 R1OUT
12 T1IN
ADM3222A
V-
7
T2OUT
8
11 T2IN
R2IN
9
10
R2OUT
SOP-18
DESCRIPTION
The ADM3222A/3232E series is an RS-232 transceiver solution intended for portable
or handheld applications such as notebook or palmtop computers. The ADM3222A/3232E
series has a high-efficiency, charge-pump power supply that requires only 0.1µF capacitors in 3.3V operation.This charge pump allows the ADM3222A/3232E series to deliver true RS-232 performance from a single power supply ranging from +3.3V to
+5.0V.The ADM3222A/3232E are 2-driver/2-receiver devices. This series is ideal for portable or handheld applications such as notebook or palmtop computers.The ESD tolerance of the ADM3222A/3232E devices are over ±15kV for both Human Body Model and
IEC1000-4-2 Air discharge test methods.The ADM3222A device has a low-power shutdown mode where the devices' driver outputs and charge pumps are disabled.During
shutdown, the supply current falls to less than 1µA.
SELECTION TABLE
MODEL
Power Supplies
RS-232
Drivers
RS-232
Receivers
External
Components
Shutdown
TTL
3-State
No. of
Pins
ADM3222A
+3.0V to +5.5V
2
2
4
Yes
Yes
18
ADM3232E
+3.0V to +5.5V
2
2
4
No
No
16
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
Input Voltages
TxIN, EN ................................................... -0.3V to +6.0V
RxIN .......................................................................... ±15V
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of the
device at these ratings or any other above those indicated in
the operation sections of the specifications below is not
implied. Exposure to absolute maximum rating conditions
for extended periods of time may affect reliability and cause
permanent damage to the device.
Output Voltages
TxOUT ...................................................................... ±15V
RxOUT ........................................... -0.3V to (VCC + 0.3V)
Short-Circuit Duration
TxOUT ............................................................ Continuous
VCC................................................................-0.3V to +6.0V
V+ (NOTE 1)................................................-0.3V to +7.0V
V- (NOTE 1)................................................+0.3V to -7.0V
V+ + |V-| (NOTE 1)....................................................+13V
Storage Temperature .............................. -65°C to +150°C
Power Dissipation Per Package
18-pin SOP (derate 15.7mW/oC above +70oC) ... 1260mW
16-pin SOP (derate 13.57mW/°C above +70°C) .. 1086mW
ICC (DC VCC or GND current).................................±100mA
NOTE 1: V+ and V- can have maximum magnitudes of 7V, but their absolute difference cannot exceed 13V.
ELECTRICAL CHARACTERISTICS
Unless otherwise noted, the following specifications apply for VCC = +3.0V to +5.0V with TAMB = TMIN to TMAX
PARAMETER
MIN.
TYP.
MAX.
UNITS
CONDITIONS
Supply Current
0.3
1.0
mA
no load, TAMB = +25oC, VCC = 3.3V
Shutdown Supply Current
1.0
10
µA
SHDN = GND, TAMB = +25oC, VCC = +3.3V
0.8
V
TxIN, EN, SHDN, Note 2
V
VCC = 3.3V, Note 2
VCC = 5.0V, Note 2
DC CHARACTERISTICS
LOGIC INPUTS AND RECEIVER OUTPUTS
Input Logic Threshold LOW
Input Logic Threshold HIGH
2.0
2.4
Input Leakage Current
± 0.01
± 1. 0
µA
TxIN, EN, SHDN, TAMB = +25oC
Output Leakage Current
± 0.05
± 10
µA
receivers disabled
0. 4
Output Voltage LOW
V
IOUT = 1.6mA
VCC-0.6
VCC-0.1
V
IOUT = -1.0mA
Output Voltage Swing
± 5.0
± 5. 4
V
3kΩ load to ground at all driver outputs,
TAMB = +25oC
Output Resistance
300
Ω
VCC = V+ = V- = 0V, TOUT = +2V
Output Voltage HIGH
DRIVER OUTPUTS
Output Short-Circuit Current
Output Leakage Current
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± 35
± 70
± 60
± 100
mA
mA
VOUT = 0V
VOUT = +15V
± 25
µA
VOUT = +12V,VCC= 0V to 5.5V,drivers disabled
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
ELECTRICAL CHARACTERISTICS
Unless otherwise noted, the following specifications apply for VCC = +3.0V to +5.0V with TAMB = TMIN to TMAX.
Typical Values apply at VCC = +3.3V or +5.0V and TAMB = 25oC.
PARAMETER
MIN.
TYP.
MAX.
UNITS
+15
V
CONDITIONS
RECEIVER INPUTS
Input Voltage Range
-15
Input Threshold LOW
0.6
0.8
1.2
1.5
Input Threshold HIGH
1.5
1.8
Input Hysteresis
0.3
Input Resistance
2.4
2.4
V
VCC=3.3V
VCC=5.0V
V
VCC=3.3V
VCC=5.0V
V
3
5
7
kΩ
120
235
kbps
Driver Propagation Delay
1.0
1.0
µs
µs
tPHL, RL = 3KΩ, CL = 1000pF
tPLH, RL = 3KΩ, CL = 1000pF
Receiver Propagation Delay
0.3
0.3
µs
tPHL, RxIN to RxOUT, CL=150pF
tPLH, RxIN to RxOUT, CL=150pF
Receiver Output Enable Time
200
ns
Receiver Output Disable Time
200
ns
Driver Skew
100
500
ns
| tPHL - tPLH |, TAMB = 25oC
Receiver Skew
200
1000
ns
| tPHL - tPLH |
30
V/µs
TIMING CHARACTERISTICS
Maximum Data Rate
Transition-Region Slew Rate
RL=3kΩ, CL=1000pF, one driver switching
VCC = 3.3V, RL = 3KΩ, TAMB = 25oC,
measurements taken from -3.0V to +3.0V
or +3.0V to -3.0V
NOTE 2: Driver input hysteresis is typically 250mV.
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
TYPICAL PERFORMANCE CHARACTERISTICS
Unless otherwise noted, the following performance characteristics apply for VCC = +3.3V, 120kbps data rates, all drivers
loaded with 3kΩ, 0.1µF charge pump capacitors, and TAMB = +25°C.
14
12
4
10
Vout+
Vout-
2
Slew Rate [V/µs]
Transmitter Output Voltage [V]
6
0
0
500
1000
1500
2000
-2
8
6
4
+Slew
-Slew
-4
2
-6
0
Load Capacitance [pF]
0
Figure 1. Transmitter Output Voltage VS. Load
Capacitance for the ADM3222 and the ADM3232
500
1000
1500
Load Capacitance [pF]
2000
2330
Figure 2. Slew Rate VS. Load Capacitance for the
ADM3222 and the ADM3232
50
118KHz
60KHz
10KHz
45
40
Supply Current [mA]
35
30
25
20
15
10
5
0
0
500
1000
1500
2000
2330
Load Capacitance [pF]
Figure 3. Supply Current VS. Load Capacitance when
Transmitting Data for the ADM3222 and the ADM3232
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
PIN NUMBER
NAME
FUNCTION
ADM3222A
ADM3232E
EN
Receiver Enable. Apply logic LOW for normal operation.
Apply logic HIGH to disable the receiver outputs (high-Z state).
1
-
C1+
Positive terminal of the voltage doubler charge-pump capacitor.
2
1
V+
+5.5V generated by the charge pump.
3
2
C1-
Negative terminal of the voltage doubler charge-pump capacitor.
4
3
C2+
Positive terminal of the inverting charge-pump capacitor.
5
4
C2-
Negative terminal of the inverting charge-pump capacitor.
6
5
V-
-5.5V generated by the charge pump.
7
6
T1OUT
RS-232 driver output.
15
14
T2OUT
RS-232 driver output.
8
7
R1IN
RS-232 receiver input.
14
13
R2IN
RS-232 receiver input.
9
8
R1OUT
TTL/CMOS reciever output.
13
12
R2OUT
TTL/CMOS reciever output.
10
9
T1IN
TTL/CMOS driver input.
12
11
T2IN
TTL/CMOS driver input.
11
10
GND
Ground.
16
15
+3.0V to +5.5V supply voltage
17
16
Shutdown Control Input. Drive HIGH for normal device operation.
Drive LOW to shutdown the drivers (high-Z output) and the onboard power supply.
18
-
-
-
VCC
SHDN
N.C.
No Connect.
Table 1. Device Pin Description
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
EN
18 SHDN
1
C1+ 2
17 VCC
V+
3
16 GND
C1-
4
15
T1OUT
C2+
5
14
R1IN
C2-
6
13 R1OUT
V-
7
12 T1IN
T2OUT
8
11 T2IN
R2IN
9
10
ADM3222A
R2OUT
SOP-18
Figure 4. Pinout Configurations for the ADM3222A
16 VCC
C1+ 1
V+ 2
15 GND
C1-
3
C2+
4
C2-
5
12 R1OUT
V-
6
11 T1IN
T2OUT
7
10
R2IN
8
9
14 T1OUT
ADM3232E
13 R1IN
T2IN
R2OUT
SOP-16
Figure 5. Pinout Configuration for the ADM3232E
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R
ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
VCC
C5
C1
+
+
17
VCC
0.1µF
2 C1+
0.1µF
V+
+
0.1µF
LOGIC
INPUTS
ADM3222A
C4
+
6 C212 T1IN
T1OUT
15
11 T2IN
T2OUT
8
R1IN
14
R2IN
9
0.1µF
RS-232
OUTPUTS
5kΩ
10 R2OUT
0.1µF
7
V-
SOP-18
13 R1OUT
LOGIC
OUTPUTS
+
*C3
4 C15 C2+
C2
3
RS-232
INPUTS
5kΩ
1 EN
SHDN
18
GND
*can be returned to
either VCC or GND
16
Figure 6. ADM3222A Typical Operating Circuits
VCC
C5
C1
+
+
1 C1+
0.1µF
C2
LOGIC
INPUTS
0.1µF
V+
*C3
ADM3232E
V-
C4
11 T1IN
T1OUT
14
10 T2IN
T2OUT
7
R1IN
13
R2IN
8
5kΩ
9 R2OUT
+
0.1µF
6
5 C2-
12 R1OUT
LOGIC
OUTPUTS
2
3 C14 C2+
+
16
VCC
0.1µF
+
0.1µF
RS-232
OUTPUTS
RS-232
INPUTS
5kΩ
GND
15
*can be returned to
either VCC or GND
Figure 7. ADM3232E Typical Operating Circuit
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
DESCRIPTION
The slew rate of the driver output is internally
limited to a maximum of 30V/µs in order to meet
the EIA standards (EIA RS-232D 2.1.7, Paragraph 5). The transition of the loaded output
from HIGH to LOW also meets the monotonicity requirements of the standard.
The ADM3222A/3232E transceivers meet the EIA/
TIA-232 and V.28/V.24 communication protocols and can be implemented in battery-powered, portable, or hand-held applications such as
notebook or palmtop computers. The ADM3222A/
3232E devices all feature proprietary on-board
charge pump circuitry that generates 2
x VCC for RS-232 voltage levels from a single
+3.0V to +5.5V power supply. This series is
ideal for +3.3V-only systems, mixed +3.3V to
+5.5V systems, or +5.0V-only systems that require true RS-232 performance. The ADM3222A/
3232E series have drivers that operate at a typical data rate of 235Kbps fully loaded.
The ADM3222A/3232E drivers can maintain high
data rates up to 235Kbps fully loaded. Figure 8
shows a loopback test circuit used to test the
RS-232 drivers. Figure 9 shows the test results
of the loopback circuit with all drivers active at
120Kbps with RS-232 loads in parallel with
1000pF capacitors. Figure 10 shows the test
results where one driver was active at 235Kbps
and all drivers loaded with an RS-232 receiver
in parallel with a 1000pF capacitor. A solid
RS-232 data transmission rate of 120Kbps
provides compatibility with many designs
in personal computer peripherals and LAN
applications.
The ADM3222A and ADM3232E are 2-driver/2-receiver devices ideal for portable or hand-held
applications.The ADM3222A features a 1µA
shutdown mode that reduces power consumption and extends battery life in portable systems.
Its receivers remain active in shutdown mode,
allowing external devices such as modems to be
monitored using only 1µA supply current.
The ADM3222A driver's output stages are turned off (tri-state) when the device is in shutdown mode. When the power is off, the
ADM3222A device permits the outputs to be
driven up to ±12V. The driver's inputs do not
have pull-up resistors.Designers should connect unused inputs to VCC or GND.
THEORY OF OPERATION
The ADM3222A/3232E series are made up of three
basic circuit blocks: 1. Drivers, 2. Receivers,
and 3. the Sipex proprietary charge pump.
In the shutdown mode, the supply current falls to
less than 1µA, where SHDN = LOW. When the
ADM3222A device is shut down, the device's
driver outputs are disabled (tri-stated) and the
charge pumps are turned off with V+ pulled
down to VCC and V- pulled to GND. The time
required to exit shutdown is typically 100µs.
Connect SHDN to VCC if the shutdown mode is
not used. SHDN has no effect on RxOUT or
RxOUTB. As they become active, the two driver
outputs go to opposite RS-232 levels where one
driver input is HIGH and the other LOW. Note
that the drivers are enabled only when the
magnitude of V- exceeds approximately 3V.
Drivers
The drivers are inverting level transmitters that
convert TTL or CMOS logic levels to ±5.0V
EIA/TIA-232 levels inverted relative to the input logic levels. Typically, the RS-232 output
voltage swing is ±5.5V with no load and at least
±5V minimum fully loaded. The driver outputs
are protected against infinite short-circuits to
ground without degradation in reliability. Driver
outputs will meet EIA/TIA-562 levels of ±3.7V
with supply voltages as low as 2.7V.
The drivers typically can operate at a data rate
of 235Kbps. The drivers can guarantee a data
rate of 120Kbps fully loaded with 3KΩ in
parallel with 1000pF, ensuring compatibility
with PC-to-PC communication software.
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R
ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
VCC
C5
C1
+
+
0.1µF
VCC
C1+
V+
0.1µF
+
0.1µF
C3
C1-
+
C2
ADM3222A
ADM3232E
C2+
0.1µF
VC4
+
C2TxOUT
TxIN
LOGIC
INPUTS
RxIN
RxOUT
LOGIC
OUTPUTS
0.1µF
5kΩ
EN
*SHDN
VCC
GND
1000pF
* ADM3222A only
Figure 8. ADM3222A/3232E Driver Loopback Test Circuit
[
T
]
[
T
T1 IN 1
T1 OUT 2
T
T
T
T
R1 OUT 3
R1 OUT 3
Ch1 5.00V
Ch3 5.00V
Ch2 5.00V M 5.00µs Ch1
Ch1 5.00V
Ch3 5.00V
0V
Figure 9. Driver Loopback Test Results at 120kbps
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]
T
T1 IN 1
T1 OUT 2
T
Ch2 5.00V M 2.50µs Ch1
0V
Figure 10. Driver Loopback Test Results at 235kbps
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
Receivers
The receivers convert EIA/TIA-232 levels to
TTL or CMOS logic output levels. All receivers
have an inverting tri-state output. These receiver
outputs (RxOUT) are tri-stated when the enable
control EN = HIGH. In the shutdown mode, the
receivers can be active or inactive. EN has no
effect on TxOUT. The truth table logic of the
ADM3222A/3232E driver and receiver outputs
can be found in Table 2.
Since receiver input is usually from a transmission line where long cable lengths and system
interference can degrade the signal, the inputs
have a typical hysteresis margin of 300mV. This
ensures that the receiver is virtually immune to
noisy transmission lines. Should an input be left
unconnected, a 5kΩ pulldown resistor to ground
will commit the output of the receiver to a HIGH
state.
Charge Pump
The charge pump uses a unique approach
compared to older less–efficient designs. The
charge pump still requires four external capacitors, but uses a four–phase voltage shifting
technique to attain symmetrical 5.5V power
supplies. The internal power supply consists
of a regulated dual charge pump that provides
output voltages 5.5V regardless of the input
voltage (VCC) over the +3.0V to +5.5V range.
SHDN
EN
TxOUT
RxOUT
0
0
Tri-state
Active
0
1
Tri-state
Tri-state
1
0
Active
Active
1
1
Active
Tri-state
Table 2. Truth Table Logic for Shutdown and Enable
Control
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In most circumstances, decoupling the power
supply can be achieved adequately using a 0.1µF
bypass capacitor at C5 (refer to Figures 6 and 7).
In applications that are sensitive to power-supply noise, decouple VCC to ground with a capacitor of the same value as charge-pump capacitor
C1. Physically connect bypass capacitors as
close to the IC as possible.
The charge pumps operate in a discontinuous
mode using an internal oscillator. If the output
voltages are less than a magnitude of 5.5V, the
charge pumps are enabled. If the output voltage
exceed a magnitude of 5.5V, the charge pumps
are disabled. This oscillator controls the four
phases of the voltage shifting. A description of
each phase follows.
Phase 1
— VSS charge storage — During this phase of
the clock cycle, the positive side of capacitors C1
and C2 are initially charged to VCC. Cl+ is then
switched to GND and the charge in C1– is transferred to C2–. Since C2+ is connected to VCC, the
voltage potential across capacitor C2 is now 2
times VCC.
Phase 2
— VSS transfer — Phase two of the clock connects the negative terminal of C2 to the VSS
storage capacitor and the positive terminal of C2
to GND. This transfers a negative generated
voltage to C3. This generated voltage is regulated to a minimum voltage of -5.5V. Simultaneous with the transfer of the voltage to C3, the
positive side of capacitor C1 is switched to VCC
and the negative side is connected to GND.
Phase 3
— VDD charge storage — The third phase of the
clock is identical to the first phase — the charge
transferred in C1 produces –VCC in the negative
terminal of C1, which is applied to the negative
side of capacitor C2. Since C2+ is at VCC, the
voltage potential across C2 is 2 times VCC.
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
Phase 4
— VDD transfer — The fourth phase of the clock
connects the negative terminal of C2 to GND,
and transfers this positive generated voltage
across C2 to C4, the VDD storage capacitor. This
voltage is regulated to +5.5V. At this voltage,
the internal oscillator is disabled. Simultaneous
with the transfer of the voltage to C4, the positive
side of capacitor C1 is switched to VCC and the
negative side is connected to GND, allowing the
charge pump cycle to begin again. The charge
pump cycle will continue as long as the operational conditions for the internal oscillator are
present.
potential to store electro-static energy and
discharge it to an integrated circuit. The
simulation is performed by using a test model as
shown in Figure 17. This method will test the
IC’s capability to withstand an ESD transient
during normal handling such as in manufacturing
areas where the ICs tend to be handled
frequently.
The IEC-1000-4-2, formerly IEC801-2, is
generally used for testing ESD on equipment
and systems. For system manufacturers, they
must guarantee a certain amount of ESD
protection since the system itself is exposed to
the outside environment and human presence.
The premise with IEC1000-4-2 is that the
system is required to withstand an amount of
static electricity when ESD is applied to points
and surfaces of the equipment that are
accessible to personnel during normal usage.
The transceiver IC receives most of the ESD
current when the ESD source is applied to the
connector pins. The test circuit for IEC1000-4-2
is shown on Figure 18. There are two methods
within IEC1000-4-2, the Air Discharge method
and the Contact Discharge method.
Since both V+ and V– are separately generated
from VCC; in a no–load condition V+ and V– will
be symmetrical. Older charge pump approaches
that generate V– from V+ will show a decrease in
the magnitude of V– compared to V+ due to the
inherent inefficiencies in the design.
The clock rate for the charge pump typically
operates at 250kHz. The external capacitors can
be as low as 0.1µF with a 16V breakdown
voltage rating.
ESD Tolerance
With the Air Discharge Method, an ESD
voltage is applied to the equipment under
test (EUT) through air. This simulates an
electrically charged person ready to connect a
cable onto the rear of the system only to find
an unpleasant zap just before the person
touches the back panel. The high energy
potential on the person discharges through
an arcing path to the rear panel of the system
before he or she even touches the system. This
energy, whether discharged directly or through
air, is predominantly a function of the discharge
current rather than the discharge voltage.
Variables with an air discharge such as
approach speed of the object carrying the ESD
potential to the system and humidity will tend to
change the discharge current. For example, the
rise time of the discharge current varies with
the approach speed.
The ADM3222A/3232E series incorporates
ruggedized ESD cells on all driver output
and receiver input pins. The ESD structure
is improved over our previous family for
more rugged applications and environments
sensitive to electro-static discharges and associated transients.The improved ESD tolerance is at least ±15kV without damage nor
latch-up.
There are different methods of ESD testing
applied:
a) MIL-STD-883, Method 3015.7
b) IEC1000-4-2 Air-Discharge
c) IEC1000-4-2 Direct Contact
The Human Body Model has been the generally
accepted ESD testing method for semiconductors. This method is also specified in MIL-STD883, Method 3015.7 for ESD testing. The premise
of this ESD test is to simulate the human body’s
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ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
VCC = +5V
C4
+5V
+
C1
C2
–
–5V
+
–
–
+
VDD Storage Capacitor
+
–
VSS Storage Capacitor
C3
–5V
Figure 12. Charge Pump — Phase 1
VCC = +5V
C4
+
C1
C2
–
+
–
–
+
VDD Storage Capacitor
+
–
VSS Storage Capacitor
C3
–10V
Figure 13. Charge Pump — Phase 2
[
T
]
+6V
a) C2+
T
GND 1
GND 2
b) C2-
T
-6V
Ch1 2.00V Ch2 2.00V M 1.00µs Ch1 5.48V
Figure 14. Charge Pump Waveforms
VCC = +5V
C4
+5V
C1
+
–5V
–
–
+
+
C2
–
+
–
VDD Storage Capacitor
VSS Storage Capacitor
C3
–5V
Figure 15. Charge Pump — Phase 3
VCC = +5V
C4
+10V
C1
+
–
C2
+
–
–
+
+
–
VDD Storage Capacitor
VSS Storage Capacitor
C3
Figure 16. Charge Pump — Phase 4
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12
友台半导体有限公司
UMW
R
ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
R
RSS
R
RC
C
SW2
SW2
SW1
SW1
Device
Under
Test
C
CSS
DC Power
Source
Figure 17. ESD Test Circuit for Human Body Model
The Contact Discharge Method applies the ESD
current directly to the EUT. This method was
devised to reduce the unpredictability of the
ESD arc. The discharge current rise time is
constant since the energy is directly transferred
without the air-gap arc. In situations such as
hand held systems, the ESD charge can be
directly discharged to the equipment from a
person already holding the equipment. The
current is transferred on to the keypad or the
serial port of the equipment directly and then
travels through the PCB and finally to the IC.
The circuit models in Figures 17 and 18
represent the typical ESD testing circuits used
for all three methods. The CS is initially charged
with the DC power supply when the first
switch (SW1) is on. Now that the capacitor is
charged, the second switch (SW2) is on while
SW1 switches off. The voltage stored in the
capacitor is then applied through RS, the current
limiting resistor, onto the device under test
(DUT). In ESD tests, the SW2 switch is pulsed
so that the device under test receives a duration
of voltage.
Contact-Discharge Module
RSS
RC
C
SW2
SW1
DC Power
Source
RV
Device
Under
Test
CSS
RS and RV add up to 330Ω for IEC1000-4-2.
Figure 18. ESD Test Circuit for IEC1000-4-2
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13
友台半导体有限公司
UMW
R
ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
I➙
For the Human Body Model, the current
limiting resistor (RS) and the source capacitor
(CS) are 1.5kΩ an 100pF, respectively. For
IEC-1000-4-2, the current limiting resistor (RS)
and the source capacitor (CS) are 330Ω an 150pF,
respectively.
30A
15A
The higher CS value and lower RS value in the
IEC1000-4-2 model are more stringent than the
Human Body Model. The larger storage
capacitor injects a higher voltage to the test
point when SW2 is switched on. The lower
current limiting resistor increases the current
charge onto the test point.
0A
t=0ns
t➙
t=30ns
Figure 19. ESD Test Waveform for IEC1000-4-2
Device Pin
Tested
Human Body
Model
Air Discharge
Driver Outputs
Receiver Inputs
±15kV
±15kV
±15kV
±15kV
IEC1000-4-2
Direct Contact
±8kV
±8kV
Level
4
4
Table 3. Transceiver ESD Tolerance Levels
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14
友台半导体有限公司
UMW
R
ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
PACKAGE: SOP-18
UNIT: mm
D
SYMBOL
A2 A
0.25
L
A1
MILLIMETER
MILLIMETER
MIN
MIN
NOM
NOM
MAX
MAX
A
2.65
A1
0.10
A2
2.20
b
0.35
c
0.25
D
11.35
11.45
11.55
E
10.10
10.30
10.50
E1
7.40
7.50
7.60
e
L
0.30
2.30
2.40
0.43
0.29
1.27BSC
0.70
1.00
E1 E
e
b
PACKAGE: SOP-16
UNIT: mm
L
E
E1
b
e
c
SYMBOL
MILLIMETER
MIN NOM MAX
A
1.80
A1
0.10
0.15
0.25
A2
1.25
1.45
1.65
b
0.33
c
0.17
0.25
D
9.50
10.20
E
5.80
E1
3.70
e
L
0.51
6.00
6.20
4.10
1.27BSC
0.45
0.60
0.80
D
A2 A
A1
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15
友台半导体有限公司
UMW
R
ADM3222A/3232E
True +3.0V to +5.5V RS-232 Transceivers
Ordering information
Order code
UMW ADM3222ARWZ
Package
SOP-18
Baseqty
2000
Deliverymode
Tape and reel
UMW ADM3232EARNZ
SOP-16
2500
Tape and reel
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16
Operating temperature range
-40°- +85°
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