• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 63 subscribers
  • Views 892 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

UCC2895 - zero and pole frequency values

oguzhan demirci
Intellectual 455 points
Other Parts Discussed in Thread: UCC2895

Hi All,

ı couldnt find how to set the EAOUT and EAN in the datasheet. there is this table which give some information but needed part is zero and pole frequency values.

Any idea?

Oğuzhan



UCC2895

  • 0
    TI__Prodigy 300 points
    Hi Oguzhan, I've contacted the appropriate application engineer and he will get back to you.
  • 0 in reply to Peter Fundaro
    TI__Mastermind 25570 points

    Hi Oguzhan


    Can you tell me which document you saw the reference to pole and zero frequencies ?

    Normally EAN is connected directly to EAO - see for example the schematic in the EVM user's guide at http://www.ti.com/lit/ug/sluu109b/sluu109b.pdf

    Regards
    Colin

  • 0 in reply to Colin Gillmor
    Intellectual 455 points

    Hi colin,

    sorry for misleading i would say there are some information in the datasheet however about EAN and EAO values, however no information about zero and pole frequencies, we need zero and pole frequency informations.

    regards,

    Oğuzhan

  • 0 in reply to oguzhan demirci
    TI__Mastermind 25570 points

    Hi Oğuzhan

    It's not possible to give you a fixed set of pole and zero values because these depend on the system that is being controlled. For example, what is the switching frequency of the power train. What optocoupler are you using to being the feedback signal across the isolation barrier (optocouplers typically have a pole in their response somewhere between 10kHz and 20kHz). What are your transient response and loop bandwidth targets. Are you using voltage mode or current mode control. etc etc..


    Anyhow, there is a lot of information about how to design a control loop available generally and the material in the TI control loop cookbook at http://www.ti.com/lit/ml/slup098/slup098.pdf

    If I had to guess, I would suggest you target a loop bandwidth of about 1kHz and then experiment with component values to get the response you need.

    BTW - for initial testing - it is much easier to test the control loop response by doing load transient test - say 25% load to 75% load and back - once you are happy with that response you can look at 0% to 100% response.


    Regards
    Colin