AN2623

Experimental results

21/25

4.5

Short circuit test

All tests have been done at nominal, maximum and minimum input voltages. For all

waveforms, the circuit starts to work in hiccup mode. Because the working time and the idle

time are imposed by the charging and discharging time of the auxiliary capacitor C11 (refer

to Figure 4), they are proportional to the input mains voltage.

Figure 11.

Behavior of the system in short circuit condition at different input

voltages

As expected the circuit protects itself as well.

Brown: output voltage

Purple: drain voltage