REV. G
–14–
ADM3307E/ADM3310E/ADM3311E/ADM3312E/ADM3315E
ESD TESTING (IEC 1000-4-2)
IEC 1000-4-2 (previously 801-2) specifies compliance testing using
two coupling methods, contact discharge and air-gap discharge.
tested. Air-gap discharge uses a higher test voltage but does not
make direct contact with the unit under testing. With air discharge,
the discharge gun is moved toward the unit under testing, which
develops an arc across the air gap, thus the term air discharge.
This method is influenced by humidity, temperature, barometric
pressure, distance, and rate of closure of the discharge 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 destruction
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 that may result in degraded
performance. The cumulative effects of continuous exposure 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 discharge
that can damage or completely destroy the interface product
connected to the I/O port. Traditional ESD test methods, 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 impor-
tant differences between the traditional 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, ensuring maximum
protection both during handling and later during field service.
R1
R2
C1
DEVICE
UNDER TEST
HIGH
VOLTAGE
GENERATOR
ESD TEST METHOD
HUMAN BODY MODEL
ESD ASSOC. STD 55.1
IEC1000-4-2
R2
C1
1.5kV
330V
100pF
150pF
Figure 9. ESD Test Standards
100
I
P
%
90
36.8
10
t
DL
t
RL
TIME t
Figure 10. Human Body Model ESD Current Waveform
100
I
P
90
10
TIME t
30ns
60ns
0.1 TO 1ns
Figure 11. IEC1000-4-2 ESD Current Waveform
The ADM33xxE devices are tested using both of the previously
mentioned test methods. All pins are tested with respect to all
other pins as per the Human Body Model, ESD Assoc. Std. 55.1
specification. In addition, all I/O pins are tested as per the
IEC 1000-4-2 test specification. The products were tested under
the following conditions:
(a) Power-On
—
Normal Operation
(b) Power-Off
There are four levels of compliance defined by IEC 1000-4-2. The
ADM33xxE parts meet the most stringent compliance level for
both contact and air-gap discharge. This means the products are
able to withstand contact discharges in excess of 8 kV and air-
gap discharges in excess of 15 kV.
Table V. IEC 1000-4-2 Compliance Levels
Level
Contact Discharge (kV)
Air Discharge (kV)
1
2
3
4
2
4
6
8
2
4
8
15