HA16174P/FP

Rev.1.00 Jan 06, 2006 page 21 of 36

(3) PFC Shutdown

By forcibly lowering the PFC-ON pin to 0.95 V, the PFC operation can be stopped even during the hold period.

Output on the OUT pin is stopped, the SS pin is reset, and the PFC operation stops. When the PFC-ON pin is driven

higher than 1.75 V, the IC is restarted in a soft-start operation.

Soft start

0.95 V

1.75 V

Full-wave rectified AC

PFC-ON

OUT

PFC output voltage

SS

Figure 8 PFC Shutdown Function Operation Waveform