ADM202E/ADM1181A
ESD TESTING (IEC1000-4-2)
IEC1000-4-2 (previously 801-2) specifies compliance testing
using two coupling methods, contact discharge and air-gap
discharge. Contact discharge calls for a direct connection to the
unit being tested. Air-gap discharge uses a higher test voltage
but does not make direct contact with the unit under test. With
air discharge, the discharge gun is moved towards the unit un-
der test developing an arc across the air gap, hence the term air-
gap discharge. This method is influenced by humidity, tempera-
ture, barometric pressure, distance and rate of closure of the dis-
charge gun. The contact-discharge method while less realistic is
more repeatable and is gaining acceptance in preference to the
air-gap method.
Although very little energy is contained within an ESD pulse,
the extremely fast rise time coupled with high voltages can cause
failures in unprotected semiconductors. Catastrophic destruc-
tion can occur immediately as a result of arcing or heating. Even
if catastrophic failure does not occur immediately, the device
may suffer from parametric degradation which may result in de-
graded performance. The cumulative effects of continuous ex-
posure can eventually lead to complete failure.
I/O lines are particularly vulnerable to ESD damage. Simply
touching or plugging in an I/O cable can result in a static dis-
charge which can damage or completely destroy the interface
product connected to the I/O port. Traditional ESD test meth-
ods such as the MIL-STD-883B method 3015.7 do not fully
test a product’s susceptibility to this type of discharge. This test
was intended to test a product’s susceptibility to ESD damage
during handling. Each pin is tested with respect to all other
pins. There are some important differences between the tradi-
tional test and the IEC test:
a. The IEC test is much more stringent in terms of discharge
energy. The peak current injected is over four times greater.
b. The current rise time is significantly faster in the IEC test.
c. The IEC test is carried out while power is applied to the device.
It is possible that the ESD discharge could induce latch-up in
the device under test. This test therefore is more representative
of a real-world I/O discharge where the equipment is operating
normally with power applied. For maximum peace of mind,
however, both tests should be performed therefore ensuring
maximum protection both during handling and later during field
service.
HIGH
VOLTAGE
GENERATOR
R1
R2
100
90
I
PEAK
– %
36.8
10
t
RL
t
DL
TIME t
Figure 13. Human Body Model ESD Current Waveform
100
90
I
PEAK
– %
10
0.1 TO 1ns
30ns
60ns
TIME t
Figure 14. IEC1000-4-2 ESD Current Waveform
The ADM202E/ADM1181E products are tested using both the
above mentioned test methods. All pins are tested with respect
to all other pins as per the MIL-STD-883B specification. In ad-
dition all I/O pins are tested as per the IEC test specification.
The products were tested under the following conditions:
a. Power-On
b. Power-Off
There are four levels of compliance defined by IEC1000-4-2.
The ADM202E/ADM1181A products meet the most stringent
compliance level for both contact and for air-gap discharge.
This means that the products are able to withstand contact dis-
charges in excess of 8 kV and air-gap discharges in excess of
15 kV.
C1
DEVICE
UNDER TEST
ESD TEST METHOD
H. BODY MIL-STD883B
IEC1000-4-2
R2
1.5kΩ
330Ω
C1
100pF
150pF
Figure 12. ESD Test Standards
REV. 0
–7–
AD [ ANALOG DEVICES ]
