±15kV ESD-Protected, 1µA, 3.0V to 5.5V, 250kbps,
RS-232 Transceivers with AutoShutdown
MAX3221E/MAX3223E/MAX3243E
R
C
1M
CHARGE-CURRENT
LIMIT RESISTOR
HIGH-
VOLTAGE
DC
SOURCE
R
D
1500Ω
DISCHARGE
RESISTANCE
DEVICE
UNDER
TEST
R
C
50M to 100M
CHARGE CURRENT
LIMIT RESISTOR
HIGH-
VOLTAGE
DC
SOURCE
R
D
330Ω
DISCHARGE
RESISTANCE
DEVICE
UNDER
TEST
Cs
100pF
STORAGE
CAPACITOR
Cs
150pF
STORAGE
CAPACITOR
Figure 6a. Human Body ESD Test Models
Figure 7a. IEC1000-4-2 ESD Test Model
I
I
P
100%
90%
AMPERES
36.8%
10%
0
0
t
RL
TIME
Ir
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
100%
90%
t
DL
CURRENT WAVEFORM
I
PEAK
10%
t r = 0.7ns to 1ns
t
60ns
Figure 6b. Human Body Model Current Waveform
30ns
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures are
incorporated on all pins to protect against electrostatic
discharges encountered during handling and assembly.
The driver outputs and receiver inputs of the
MAX3221E/MAX3223E/MAX3243E have extra protection
against static electricity. Maxim’s engineers have devel-
oped state-of-the-art structures to protect these pins
against ESD of ±15kV without damage. The ESD struc-
tures withstand high ESD in all states: normal operation,
shutdown, and powered down. After an ESD event,
Maxim’s E versions keep working without latchup, where-
as competing RS-232 products can latch and must be
powered down to remove latchup.
ESD protection can be tested in various ways; the trans-
mitter outputs and receiver inputs of this product family
are characterized for protection to the following limits:
1) ±15kV using the Human Body Model
2) ±8kV using the contact-discharge method specified in
IEC1000-4-2
3) ±15kV using IEC1000-4-2’s air-gap method
10
Figure 7b. IEC1000-4-2 ESD Generator Current Waveform
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
Human Body Model
Figure 6a shows the Human Body Model, and Figure
6b shows the current waveform it generates when dis-
charged into a low impedance. This model consists of
a 100pF capacitor charged to the ESD voltage of inter-
est, which is then discharged into the test device
through a 1.5kΩ resistor.
IEC1000-4-2
The IEC1000-4-2 standard covers ESD testing and per-
formance of finished equipment; it does not specifi-
cally refer to integrated circuits. The MAX3221E/
MAX3223E/MAX3243E help you design equipment that
meets Level 4 (the highest level) of IEC1000-4-2, with-
out the need for additional ESD-protection components.
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
