ADM202E/ADM1181A

–8–

REV. 0

Table I. IEC1000-4-2 Compliance Levels

Level

Contact Discharge

Air Discharge

1

2 kV

2 kV

2

4 kV

4 kV

3

6 kV

8 kV

4

8 kV

15 kV

Table II. ADM202E/ADM1181A ESD Test Results

ESD Test Method

I/O Pins

Other Pins

MIL-STD-883B

±15 kV

±3 kV

IEC1000-4-2

Contact

±8 kV

Air

±15 kV

FAST TRANSIENT BURST TESTING (IEC1000-4-4)

IEC1000-4-4 (previously 801-4) covers electrical fast-transient/

burst (EFT) immunity. Electrical fast transients occur as a re-

sult of arcing contacts in switches and relays. The tests simulate

the interference generated when for example a power relay dis-

connects an inductive load. A spark is generated due to the well

known back EMF effect. In fact the spark consists of a burst of

sparks as the relay contacts separate. The voltage appearing on

the line therefore consists of a bust of extremely fast transient

impulses. A similar effect occurs when switching on fluorescent

lights.

The fast transient burst test defined in IEC1000-4-4 simulates

this arcing and its waveform is illustrated in Figure 11. It con-

sists of a burst of 2.5 kHz to 5 kHz transients repeating at

300 ms intervals. It is specified for both power and data lines.

300ms

15ms

t

V

5ns

0.2/0.4ms

50ns

V

t

Figure 15. IEC1000-4-4 Fast Transient Waveform

A simplified circuit diagram of the actual EFT generator is illus-

trated in Figure 16.

The transients are coupled onto the signal lines using an EFT

coupling clamp. The clamp is 1 m long and it completely sur-

rounds the cable providing maximum coupling capacitance

(50 pF to 200 pF typ) between the clamp and the cable. High

energy transients are capacitively coupled onto the signal lines.

Fast rise times (5 ns) as specified by the standard result in very

effective coupling. This test is very severe since high voltages are

coupled onto the signal lines. The repetitive transients can often

cause problems where single pulses don’t. Destructive latchup

may be induced due to the high energy content of the tran-

sients. Note that this stress is applied while the interface prod-

ucts are powered up and are transmitting data. The EFT test

applies hundreds of pulses with higher energy than ESD. Worst

case transient current on an I/O line can be as high as 40 A.

HIGH

VOLTAGE

SOURCE

L

50

Ω

OUTPUT

Figure 16. IEC1000-4-4 Fast Transient Generator

Test results are classified according to the following:

1. Normal performance within specification limits.

2. Temporary degradation or loss of performance that is

self-recoverable.

3. Temporary degradation or loss of function or performance

that requires operator intervention or system reset.

4. Degradation or loss of function that is not recoverable due

to damage.

The ADM202E/ADM1181A have been tested under worst case

conditions using unshielded cables and meet Classification 2.

Data transmission during the transient condition is corrupted,

but it may be resumed immediately following the EFT event

without user intervention.