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AN1523 APPLICATION NOTE

Short-Circuit Tests @ Full Load

The short circuit tests have been done in two phases, making the test shorting by a power switch the output

electrolytic capacitor or making the short by the active load option. This gives an idea about the circuit behaviour

with a hard short (at very low impedance) or with a ”soft” short that could happen on the STB main board, having

slightly higher impedance. All the tests have been done at maximum, nominal and minimum input voltage. For

value close to the nominal one, thus preventing component melting for excessive dissipation in case of long term

shorts. The auto-restart is correct at short removal in all conditions.

Figure 19. SHORT ON +5V

Figure 20. SHORT ON +5V

Vin = 88 Vrms - 50 Hz @FULL LOAD

Vin = 265 Vrms - 50 Hz @FULL LOAD

CH1:

CH1:

CH2:

CH2:

CH4:

CH4:

Figure 21. SHORT ON +12V

Figure 22. SHORT ON +12V

Vin = 88 Vrms - 50 Hz @FULL LOAD

Vin = 265 Vrms - 50 Hz @FULL LOAD

CH1:

CH1:

CH2:

CH2:

CH4:

CH4: