• State TI Thinks Resolved
  • Locked Locked
  • Replies 8 replies
  • Answers 1 answer
  • Subscribers 39 subscribers
  • Views 4335 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.

TINA/Spice/UCC28070: PFC

Ulrich Gerhardt
Prodigy 60 points
Part Number: UCC28070
Other Parts Discussed in Thread: TINA-TI,

Tool/software: TINA-TI or Spice Models

Hello everyone,

I am currently working on a semi-bridgeless PFC design like in Application Report SLUA517 on page 7 with UCC28070. To test my schematic I want to simulate it in Pspice (OrCAD 16.6), but there are some problems:

- the TRAN model of UCC28070 has no GND pin but F_KHZ, IRIPB, IRIPA pins which I don‘t know how to connect

- when do I need the BOOST_AVG model and how is it connected (especially CSX, IRIPX, CSOFFX, K_KHZ) ?

- after simulating my design the UCC28070 model seems to do nothing, pins GDA and GDB are constantly at 0.8V

Thank you for your help and best regards

Ulrich

  • 0
    TI__Mastermind 19420 points

    Hello Ulrich,

    The extra pins are there to be used for the AVERAGE model not Transient model ( they are connected and used by the  two AVERAGE BOOST in the test-bench) .  With the same token,  the missing pins are for frequency dithering which were not modeled/used and thus removed.

    In reality the  GDA and GDB should be pulsing to 12V but it seems the "High" is not 12V in the model, nevertheless it pulses and works correctly , just differnt HIGH value. However, in your case they are  stuck at  0.8 volts. Please check your circuit.

    The ground pin is internall hard wired to GND.

    The topic of extra pins and/or missing pins for serveral parts,  including many questions for UCC28070, are discussed  in the forum and you can search for them and get more insight.

    I hope it helps you to continue with your project.

    Kind Regards,

    Arah

  • 0 in reply to Arash Loloee
    Prodigy 60 points

    Hello Arah,

    Thanks for your answer.

    Now I got a working simulation with the Average Boost Model.

    But in my simulation the output voltage is very dependant on the input voltage and the load.

    The output voltage varies between 240-400 V (input 110 VAC – 250 VAC).

    Is this correct?

    Anyway I wanted to simulate a schematic like this. Is this possible?

    Thank you for your help and best regards

    Ulrich

  • 0 in reply to Ulrich Gerhardt
    TI__Mastermind 19420 points

    Ulrich,

    As far as the model is concerned, the model is functional and works correctly with the provided test bench. I can't comment on the test bench  you are using but I would make sure that the input and  bridge is configured and connected correctly and then move on to the rest of schematic in the debug process.

    Reagrds,

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 60 points

    Hello Arash,

    I checked my circuit diagram and as far as I can see everything is correct.

    I want to use the UCC28070 as a bridgeless PFC controller (like Application Report SLUA517 on page 7) and this is what I want to simulate.

    Is this model of UCC28070 suitable to simulate such a configuration?

    Thank you for your help and best regards

    Ulrich

    This is the circuit diagram from the application report SLUA517:

  • 0 in reply to Ulrich Gerhardt
    Prodigy 60 points
    Hello everyone,

    can you please answer my last question?

    Regards,

    Ulrich
  • 0 in reply to Ulrich Gerhardt
    TI__Mastermind 19420 points

    Hello Ulrich,

    As far as the model goes, it has been tested with the released test bench and workd fine as was released long time ago.

    If the test bench needs to be modified from the released test bench,  you should consult with the  system engineer who has better familiarity with the IC and can answer your question. May be it is better to contact the system engineer who works with you and your company as starting point.

    Regards,

    Arash

  • 0 in reply to Arash Loloee
    Prodigy 60 points
    Tank you for your help.

    Best regards,

    Ulrich