ha16174p Renesas Electronics Corporation., ha16174p Datasheet - Page 23

• Manufacturer Part Number: ha16174p
• Description: Power Factor Correction Controller Ic
• Manufacturer: Renesas Electronics Corporation.

HA16174P/FP
5-1. Power-Supply Startup Operation
When the AC voltage is applied, the PFC-ON pin voltage starts to rise; after it has reached 1.75 V, PFC operation starts.
When PFC operation starts, the voltage on the FB pin starts to rise. When it has reached 2.4 V (equivalent to 96% of
the PFC output voltage), the capacitor attached to the DELAY pin starts to charge up. When the voltage on the DELAY
pin reaches 2.5 V, the internal MOS FET of the PG pin is turned off. Delaying the output of the PG signal avoids an
unstable state of PFC output voltage, and assists in achieving correct on-and-off control in the back stages of the system.
Full-wave rectified AC
Rev.1.00 Jan 06, 2006 page 23 of 36
PFC output voltage
DELAY pin current
DELAY pin voltage
PG pin voltage
(pulled up by a resistor to the VREF voltage)
PFC-ON
FB
Figure 10 Waveforms in Operation to Delay PG Assertion
CAO
SS
1.75 V
96% of the output voltage
2.4 V
–10 µA
2.5 V
100 µA
CAO
SS