ADM3311 AD [Analog Devices], ADM3311 Datasheet - Page 9

• Manufacturer Part Number: ADM3311
• Manufacturer: AD [Analog Devices]

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 toward the unit under
test, developing an arc across the air gap, hence 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 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
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 dis-
charge that 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
(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 is therefore more representative of a
real-world I-O discharge where the equipment is operating nor-
mally with power applied. For maximum peace of mind however,
both tests should be performed, thus ensuring maximum protec-
tion both during handling and later, during field service.
energy. The peak current injected is over four times greater.
GENERATOR
VOLTAGE
HIGH
ESD TEST METHOD
H. BODY MIL-STD883B
IEC1000-4-2
Tx
R1
C1
D2
D1
R2
1.5k
330
R2
C1
100pF
150pF
TRANSMITTER
OUTPUT
UNDER TEST
DEVICE
The ADM3311E is tested using both of the above-mentioned
test methods. All pins are tested with respect to all other pins as
per the MIL-STD-883B specification. In addition, all I-O pins
are tested as per the IEC test specification. The products were
tested under the following conditions:
(a) Power-On—Normal Operation
(b) Power-Off
Four levels of compliance are defined by IEC1000-4-2. The
ADM3311E meets the most stringent compliance level for con-
tact discharge. This means that the products are able to with-
stand contact discharges in excess of 8 kV.
Level
1
2
3
4
ESD Test Method
MIL-STD-883B
IEC1000-4-2
Contact
0.1 TO 1ns
10.0
36.8
100
90
100
90
10
Table II. IEC1000-4-2 Compliance Levels
Table III. ADM3311E ESD Test Results
t
RL
Contact Discharge
(kV)
2
4
6
8
30ns
I-O Pins (kV)
± 15
± 8
t
DL
60ns
ADM3311E
TIME t
Other Pins (kV)
± 3
Air Discharge
(kV)
2
4
8
15
TIME t