AN3119 datasheet(18/32 Pages) STMICROELECTRONICS

18 / 32 page

Test results and significant waveforms

AN3119

18/32

Doc ID 16849 Rev 2

Figure 26.

EVL6563S-250W TM PFC: startup attempt at 80 Vac-60 Hz - full load

In Figure 26 a startup tentative below the threshold is shown. As seen, at startup the RUN

pin does not allow the PFC startup even if the Vcc has reached the turn-on threshold. PFC

output voltage remains at the peak of the input sinewave.

In Figure 27 and 28 the waveforms of the circuit during operation of brown-out protection are

shown. In both cases the mains voltage was increased or decreased slowly; as seen, both

at turn-on or turn-off there are no bouncing or starting attempts by the PFC converter.

CH1: PFC output voltage

CH2: Vcc voltage (pin #14)

CH3: RUN (pin #10)

CH4: gate drive (pin #13)

Figure 27.

EVL6563S-250W TM PFC: startup

with slow input voltage increasing -

full load

Figure 28.

EVL6563S-250W TM PFC: turn-off

with slow input voltage decreasing

- full load

CH1: PFC output voltage

CH2: gate drive (pin #13)

CH3: RUN (pin #10)

CH4: PWM_stop (pin #9)

CH1: PFC output voltage

CH2: gate drive (pin #13)

CH3: RUN (pin #10)

CH4: PWM_stop (pin #9)

AN3119 Datasheet(PDF) 18 Page - STMicroelectronics