• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 41 subscribers
  • Views 141 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.

TIDA-00915: Bootstrap Power Supply

Xiaonan Lu
Prodigy 100 points
Part Number: TIDA-00915

The top-side GaN modules are supplied through bootstrap arrangement from the 12-V power supply. This Bootstrap Power Supply dose not have properly return, So it does not work.

Thanks!

  • 0
    TI__Prodigy 680 points

    Hi Xiaonan,

    Thank you for the comment.

    In motor drive applications using boot-strap supplies in the high-side, it is necessary to turn on the low-side power switches, may be one by one and / or with PWM, to pull the output phases to the negative DC bus to form a return path for each bootstrap capacitor. So is it in this reference design.

    Take the U-phase for example, in the up-right corner in page 4 of "TIDA-00915_Isolator_Board_E1.PDF" we can see that the 12V supply can charge the bootstrap capacitor C32 (in fact, there is another one of C17 in parallel with it in "TIDA-00915_Power_Board_E1.PDF") to 12V_T_U via D4 and R26, if the PHASEU is pulled to HVBUS_RTN when the low-side U-phase switch Q2 is turned on. Take a reference to page 4 of "TIDA-00915_Power_Board_E1.PDF" for it.

        

        

    This is the U-phase's bootstrap capacitor (C32+C17) charge loop. The V-phase and W-phase are similar.

    Best regards,

    Jerome Shan