• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 209 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

UCC28710: ucc28710- Frequency response analysis

robin gangopadhya18
Mastermind 6050 points
Part Number: UCC28710

Hello:

An interesting question: how would one measure traditional " frequency response" to get Gain-Margin & Phase-Margin?

If you add too many extra components to create a Test circuit, then FRA will be their response perhaps not of the switching circuit.

In fact, does FRA apply to such nonlinear feedback systems?

What other methods do we have to demonstrate the "stability " of these circuits? 

Can we set up to measure "output impedance" & "input impedance" ?

-r

  • +1
    TI__Mastermind 26700 points

    Hello Robin,

    The UCC287XX family of PSR flyback controllers cannot be measured for Gain and Phase margin in the usual Bode-plot way, because there is no point that can break the feedback path without interfering with timing signals a the VS pin.

    The only method we know of for assessing stability is to apply load steps to the output and assess the degree of ringing (if any) on the step response.
    Note: Loop stability is a small-signal property, so please avoid using large load steps for the testing. The deviations are easier to see, but may obscure the true response.   

    Regards,
    Ulrich