12 V supply for Hiperpfs

2 posts / 0 new

I am designing the PFC with a hiperpfs-3, the problem i have is you require an auxiliary power supply of 12v on vcc, do you have a circuit? or just add a resistor and a cap between the diode bridge BR1 and the inductor L1? What is the current required?

I am looking at using the linkswitch-xt, but maybe that will affect the power factor control in a negative way. Any suggestions for the 12 V supply?

Adding a resistor and capacitor from the bridge rectifier will not work as an auxiliary supply. The voltage will not be regulated and the loss from the resistor will be too high on high input voltage conditions. The bias current supply is specified in the datasheet and it depends on the exact PFS3 part that you plan to use (see attached table). In general, the auxiliary power is very small compared to the output power of the PFC thus will have an insignificant effect on the PF control.

You may use any of our LinkSwitch products as auxiliary circuit, depending on your requirement. A non-isolated buck/flyback (LinkSwitch-TN2) should suffice. Using a non-isolated topology will simplify the design at a cheaper BOM cost (lower number of components). See the RDR-506 below for reference.

LinkSwitch-TN2 (non-isolated buck) - https://ac-dc.power.com/design-support/reference-designs/design-examples/rdr-506-144-w-non-isolated-buck-converter-using-linkswitch-tn2/

TitleSize
PFS3_Operating_Current.png36.85 KB