This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

UCD3138: Totem pole PFC

Part Number: UCD3138
Other Parts Discussed in Thread: PMP20873

Hello, teams

 My customer is interested in 3 phase AC input Totem-pole PFC for their product about 15kW.

 They want to use the pfc output voltage by varying it to the maximum possible range.

The AC input voltage is as follows:

      Phase-to-phase input voltage: 350 ~ 450Vac
      (Minimum Phase-to-Neutral input voltage: 200Vac) 

 What are the minimum and maximum possible output voltage?



  • Hello KW,

    Thank you for you interest in the UCD3138x devices and totem-pole PFC. Our most relevant design is the PMP20873:

    A boost PFC requires boosting at least the maximum input voltage with some margin. At 450VAC, the peak voltage will be 450V*√2 = 636V. 650V would be the a target minimum output voltage. Boost PFC has a theoretical unlimited max output voltage but in reality a boost converter can only go up to around ~3-4x times. However, having a wide output voltage range is not recommended since the efficiency will decrease. Efficiency will be maximum when the boost output is minimized. It may be better to have a separate DC/DC stage after the PFC instead.  

    The overall concepts for a boost PFC should be similar for totem-pole PFC. 


    Jonathan Wong

  • Hi, Jonathan,

    thanks for your information.