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TIDA-00443: what is the design for ACSENSE in the reference circuit

John Chou62
Intellectual 1950 points
Part Number: TIDA-00443

Hi,

1. may we check what is the application for AC sense from the reference schematic on page 38?

2. also on the reference schematic, PFC_ON, what's the highest voltage it can withstand? is it ok if voltage greater than 12V?

Thanks

  • 0
    TI__Genius 12990 points
    Hi John,

    Thanks for your question on this TIDA! I will work with you to solve all your questions!!

    1) the ACsense node on page38 denotes the boost follower. The boost follower configuration is a mechanism in which the boost voltage can be varied proportionally to the AC input voltage. The boost follower configuration helps to reduce switching losses in the PFC regulator and the downstream inverter or converter. The design with boost follower configuration delivers an efficiency of approximately 98%. In comparison to fixed voltage operation, the boost follower configuration saves an additional 5.2 W of power at 230-V AC and a full load capacity.

    check out "4.3.1 Boost Follower Circuit Description" on page 19

    2) Q5 and Q3 look like the limiting factor. These enhancement NFETs can handle +-20V continuous. I will have to check with the designer to verify this limit. I will update you asap.

    Thanks,
  • 0
    TI__Genius 12990 points

    Hi John,

    Just want to let you know I am still working on an answer for max voltage on PFC_ON. I will update you asap.

    Thanks

  • 0
    TI__Genius 12990 points
    Hi John,

    PFC_ON cannot be more than gate voltage of the FETs, better to limit to less than 15V.

    Let me know if any more questions pop up!
    Thanks,