Detailed Description
±15kV ESD Protection
As with all Maxim devices, ESD-protection structures
are incorporated on all pins to protect against electro-
static discharges (ESD) encountered during handling
and assembly. The MAX3209E driver outputs and
receiver inputs have extra protection against static
electricity found in normal operation. Maxim’s engi-
neers developed state-of-the-art structures to protect
these pins against ±15kV ESD, without damage. After
an ESD event, the MAX3209E continues working without
latchup.
ESD protection can be tested in several ways. The
transmitter outputs and receiver inputs are character-
ized for protection to the following:
1) ±15kV using the Human Body Model
2) ±8kV using the Contact-Discharge Method specified
in IEC 1000-4-2 (formerly IEC 801-2)
3) ±15kV using the Air-Gap Method specified in
IEC 1000-4-2 (formerly IEC 801-2)
ESD Test Conditions
ESD performance depends on a number of conditions.
Contact Maxim for a reliability report that documents
test setup, methodology, and results.
Human Body Model
Figure 2a shows the Human Body Model, and Figure
2b 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 device through a
1.5kΩ resistor.
IEC 1000-4-2
Since January 1996, all equipment manufactured
and/or sold in the European community has been
required to meet the stringent IEC 1000-4-2 specifica-
tion. The IEC 1000-4-2 standard covers ESD testing
and performance of finished equipment; it does not
specifically refer to integrated circuits. The MAX3209E
helps you design equipment that meets Level 4 (the
highest level) of IEC 1000-4-2, without additional ESD-
protection components.
The main difference between tests done using the
Human Body Model and IEC 1000-4-2 is higher peak
current in IEC 1000-4-2. Because series resistance is
lower in the IEC 1000-4-2 ESD test model (Figure 3a), the
ESD withstand voltage measured to this standard is gen-
erally lower than that measured using the Human Body
Model. Figure 3b shows the current waveform for the
±8kV IEC 1000-4-2 Level 4 ESD Contact-Discharge test.
The Air-Gap test involves approaching the device with a
charge probe. The Contact-Discharge method connects
the probe to the device before the probe is energized.
Machine Model
The Machine Model for ESD testing uses a 200pF stor-
age capacitor and zero-discharge resistance. It mimics
the stress caused by handling during manufacturing
and assembly. Of course, all pins (not just RS-232
MAX3209E
±15kV ESD-Protected, 12V, Dual RS-232 Serial Port
with Low-Power Standby for Motherboards/Desktops
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Pin Description
