AN2872

Experimental results

Doc ID 15305 Rev 1

19/23

pulse) or a bulk capacitor capable of storing enough energy from the surge pulse to reduce

the voltage peak level.

The 2 kV surge test was performed on the board with no failures.

4.6.2

Burst - IEC 61000-4-4

References: 9) as fast switching disturbance presented in the mains. This test means the

high frequency, high voltage (8 kV), very short pulses (50 ns) are applied between the input

lines and metal plate connected to PE at a defined distance from tested device

(100 mm).

This test typically does not cause any damage to the components applied for the SMPS, but

it produces high current pulses flowing through the board and causes voltage spikes

between different parts of PCB. These spikes can render unstable the applied integrated

circuits for the SMPS (mainly the controller). The possible impact typically seen in the SMPS

is unstable operation (restart of the SMPS could be allowed) or latching of the SMPS (not

allowed).

The typical protection against the effects of the burst pulses is application of small filters

(capacitance in the range of 100 pF to several nF) to the sensitive inputs.

The 8 kV burst test was performed on the board with no failures.

4.6.3

EMI

The EMI was tested at an input voltage of 230 VAC for full output load. Measurements are

listed for the different input connections and average and peak detector in Figure 13.