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UCC28070: UCC28070 issue

Part Number: UCC28070

Would you advise me the follow issue?

My customer is during evaluation of PFC with UCC28070.

They power supply spec is 

Input voltage:universal power supply

Output:380Vdc 2500W

reference design

1200W PR779-PR778




  • Load-Output Characteristics will not get better

The more getting load, the more lower output voltage.

(About drop 50V, no-load,input 100V,output 200Vdc 1.3-2.6A)

We order to confirm the follows.

  • The waveform of current flow the diode after inductor
  • The difference voltage between GND of output condenser and UCC28070's GND
  • Is it stable about the voltage of Vsense in UCC28070?

I will send you the data,If you are possible.

Best regard