IEC 61000-4-4 Tests

AN3169

6/12

Doc ID 17194 Rev 1

2

IEC 61000-4-4 Tests

2.1

Test procedure

To compare the immunity capabilities of the different technologies, we have performed tests

as described in the IEC 61000-4-4 standard [5]. European appliance manufacturers usually

require that their equipment will not present any malfunction for burst levels up to 2 kV.

Here, we increase the burst level by 0.1 kV steps to reach at least one device spurious

triggering within one minute. To easily compare only the Triacs performance, we used a

dedicated board featuring all the AC switches, and their gate connected to their A1 terminals

through gate resistors. This allows us to be sure that the spurious triggering comes from the

switch itself and not from any control circuit. The spurious triggering is detected when the

light bulb, connected in series with one of the switch, is switched on. As a Triac will latch,

usually the on time will last several ms. This is long enough for a human eye to detect it.

The tests are carried out in the following conditions.

●

The printed circuit board is 10 cm above reference plane.

●

A mains S14K300 varistor (refer to “V” on Figure 5) is connected to the mains input on

the PCB.

●

The board embeds four Triacs (or ACSTs).

●

Each Triac-A2 (or ACST OUT) terminal is linked to a 25 W light bulb (resistive loads are

chosen to get easier device turn on as dI/dt is higher than with inductive load).

●

Each gate is connected to A1 or COM terminals respectively, for Triac and ACST,

coming from any control circuit.

●

No snubber circuits are added across the Triacs or ACSTs.

●

Ambient temperature is 25° C.

●

The board is plugged into an L-N plug which is disturbed by a burst generator (bursts

are coupled to N or to L, for positive or negative bias).

●

The burst generator is programmed as required in the IEC 61000-4-4 standard (15 ms

burst duration, 3 Hz burst frequency, 5 kHz spike frequency, one minute test duration).

Note:

Only results with coupling modes to L and N are presented here as the other coupling

modes are usually less stressful. For example, a simultaneous coupling of the burst to L, N

and the PE (Protective Earth, which is not connected to our board) will lead to a less

stressful test.