• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 429 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.

UCC27714: Using this part for H-Bridge Design

Randhir Kalsi
Expert 4545 points
Part Number: UCC27714

Hello team,

See below customer question:

Planning on using two of the UCC27714 Half Bridge drivers with external FETs to establish our H-Bridge design needed.

Our intent is to use one PWM for the High side and have the low side on full.  On board logic will control enables of each depending on direction and have the ability to disable all.  We do not have a second PWM source if this chip requires two PWMs to run high and low sides.  

I could not find anything in the datasheet that indicates this cannot be done.  Please confirm that this method will work before we get too far in the design.

  • 0
    TI__Mastermind 23155 points

    Hello Randhir,

    From a driver standpoint, with the UCC27714, the HO and LO outputs can be high at the same time to allow use in converters such as a two switch forward for example. So the operation you describe will work.

    Operation of the low side driver, in a DC state should be OK since the low side driver bias is VDD. The high side driver HB bias, if using the bootstrap diode method requires the HS pin to switch to near ground to charge the HB capacitor from VDD. It is not clear regarding the overall topology, but consider if the HB bias can be maintained, or how the HB bias is provided.

    Let me know if this addresses your questions, or you can post more questions and information on this thread.

    Regards,

    Richard Herring

  • 0 in reply to Richard Herring
    TI__Expert 4545 points

    One other question, what is the highest frequency we can use on the PWM?  It is apparent from the datasheet that 100Khz is possible, but we were hoping to run at 300Khz

  • 0 in reply to Randhir Kalsi
    TI__Mastermind 23155 points
    Hello Randhir,
    The TI 600V drivers including the UCC27714 have been used in LLC converters which can operate at switching frequencies in the 300kHz range. Be sure and review the UCC27714 datasheet Section 9.2 especially the estimating power dissipation section. Confirm that the power dissipation and the thermal resistance will not be a temperature rise concern.

    Please confirm if this answers your questions, or you can post additional questions on this thread.
    Regards
    Richard Herring