AN3119

Test results and significant waveforms

Doc ID 16849 Rev 2

21/32

The event of an open-loop is demonstrated in Figure 32 and 33; notice the protection

intervention, latching the operation of the L6563S. As mentioned previously, to restart the

system it is necessary to recycle the input power. The connection of the startup resistors

after the rectifier bridge allows a restart, in case of latch, faster than connecting the resistor

to the bulk capacitor. In this case, to restart the operation it is necessary to wait the time

resume the operation.

Figure 31.

EVL6563S-250W load transient at 115 Vac - 60 Hz - full load to no-load

CH1: PFC output voltage,

CH2: PFC_OK (pin #7),

CH3: gate drive (pin #13),

CH4: Iout

Figure 32.

EVL6563S-250W TM PFC: open-

loop at 115 Vac - 60 Hz - full load

Figure 33.

EVL6563S-250W TM PFC: open-

loop at 115 Vac - 60 Hz - full load -

long acquisition

CH1: PFC output voltage

CH2: Vcc (pin #14)

CH3: gate drive (pin #13)

CH4: PWM_LATCH (pin#8)

CH1: PFC output voltage

CH2: Vcc (pin #14)

CH3: gate drive (pin #13)

CH4: PWM_LATCH (pin#8)