• State
  • Locked Locked
  • Replies 7 replies
  • Subscribers 63 subscribers
  • Views 983 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.

Support for UCC28070

Pradhan Rivankar
Expert 1080 points
Other Parts Discussed in Thread: UCC28070

Dear Sir/Madam

I m currently working with UCC28070 ic for 2KW power level and we did the all required calculation for inductor and and control ckt for 2 KW using slua479b , Also  we refer the TI 300W Evaluation board . As i monitor the inductor waveform i  found that it didn't  match with theory . As per theory inductor current increase during MOSFET turn ON and @ MOSFET TURN OFF inductor CURRENT decrease but practically during turn off MOSFET inductor waveform decrease and again increase . Please find the attached images for same issue.

  As i run the board up to 600 W power level for more then 5-6 Hours continuously ,As further i increase the load our one leg MOSFET gets damaged.

  Please help us to resolved same issue. 

Thanks and regards

PradhanBOOST_SCH.PDFucc28070.PDF

  • 0
    TI__Mastermind 31580 points
    Hi Pradhan,

    I have asked one of our applications engineers to respond to your post.

    Regards

    Peter
  • 0 in reply to Peter Meaney
    Expert 1080 points

    Hi Peter

    Awaiting for your valuable feedback.

    Thanks in advance.

    Pradhan

  • 0 in reply to Peter Meaney
    TI__Mastermind 34465 points

    Hi Pradhan,

    I can see nothing amiss with the schematic you attached. The component values look reasonable and the circuit is wired up as it should be.

    Can you attach a scope plot of some of the switching waveforms?  I don't understand what you mean about the inductor current wave shape.

    1. Please attach the  drain current waveform and its associated gate drive.
    2. Repeat for both channels.
    3. What does the pcb layout look like and
    4. What are the part numbers for the current transformers and boost MOSFETS ?

    Regards

    John Griffin

  • 0 in reply to John Griffin1
    Expert 1080 points

    HI John

     Please find the attached images for inductor current and MOSFET D-S  waveform . Also attached the  PCB layout .As i m trying to run for 1000W power level according  to calculation (application note of 300W UCC28070)i need approximately 100uH inductor value .  MOSFET used are IR840 , Diode RHRP1560 and output capacitance value is  2 capacitor of 470uF parallel .

    Help me with your valuable inputs.images.rar inputs.

    thanks and regards

    Pradhan

  • 0 in reply to Pradhan Rivankar
    TI__Mastermind 34465 points
    Hi Pradham,
    The value of C5 is way too small for a 2kW application.
    You should see a rectified AC on C5 for correct pfc operation and for this C5 needs to be somewhere between 1uF to 10uF.
    The value is really selected by experiment at full power and low line.
    Settle with the lowest value that gives you an acceptable current waveform.
    Hope this helps.
    Regards,
    John
  • 0 in reply to John Griffin1
    Expert 1080 points

    Thanks John for your suggestion. Wil check and revert back with feedback.

    thanks in advance.

    Pradhan

  • 0 in reply to Pradhan Rivankar
    Expert 1080 points

    Hi John

    I have been designing it for 2KW output power. Till 700W it works fine @200KHZ frequency and once I go for higher wattage it causes issue.

    Input Voltage --- 180V - 265VAC

    Out put Voltage  -- 400 V DC

    Output Power --  2KW 

    Switching Frequency -- 200KHz

      As till now i reached up to approximately 700W power level but  if i tried to increase further power level both leg  MOSFET  Blown out .Kindly suggest on same issue.

    Is there a frequency limitation for the same? Awaiting for your kind inputs.

    Thanks for understanding. 

    Pradhan