What is the power factor (PF) requirement for an SMPS or even just a standalone power factor correction (PFC) stage with a power level above 75W?

I know that in some cases the customer will specify the requirements at say 10% total rated load to be 0.9. For instance, assume that the PFC is rated for 1600W, thus 10% load will be 160W and the required PF is 0.9.

What about PF in between 75W - 160W? Does it have to comply with any requirements?

NOTE: Active power factor correction is considered in this example.

  • \$\begingroup\$ Are you referring to CE requirements? \$\endgroup\$
    – Kartman
    Mar 30, 2021 at 11:16
  • \$\begingroup\$ Yes, it would have to be. \$\endgroup\$
    – Rr Bb
    Mar 30, 2021 at 11:40
  • \$\begingroup\$ Then specify in the question what standards you require. The answer is probably in the standard anyways. \$\endgroup\$
    – Kartman
    Mar 30, 2021 at 12:31
  • \$\begingroup\$ There is no information online about it (based on my research). In addition, to view a full standard you must purchase it I think. \$\endgroup\$
    – Rr Bb
    Mar 30, 2021 at 12:47

1 Answer 1


What about PF in between 75W - 160W? Does it have to comply with any requirements?

From this wiki page and take particular note of the final sentence: -

In 2001, the European Union put into effect the standard IEC/EN61000-3-2 to set limits on the harmonics of the AC input current up to the 40th harmonic for equipment above 75 W. The standard defines four classes of equipment depending on its type and current waveform. The most rigorous limits (class D) are established for personal computers, computer monitors, and TV receivers. To comply with these requirements, modern switched-mode power supplies normally include an additional power factor correction (PFC) stage.

If you dig around you can find tables like this: -

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Source document that has the above table and other good information on this subject.

Here's another good bit of reading material. And, another useful link.


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