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UC3854B: UC3854B

Part Number: UC3854B

Hi,

My current problem with the UC3854B is that the output dc voltage changes with the input and is not constant at any range of the input voltage.

What can be the reason for that?

Russell

  • Hi Russell

    it sounds like the voltage control loop is not working correctly. Can you check the voltage at the output of the Voltage error amplifier (VAO) and the duty cycle on the gate drive (GTDRV) to the PFC mosfet.

    If VAO is high, can you also check the voltage on the current amplifier output (CAO).

    Regards

    Peter

  • Hi Russell,

    I hope you have made some progress on you design since my reply. Since there has been no activity on the post for a number of days now I will close this post.

    Please open a new post if you have more questions.

    Regards

    Peter