• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 3 answers
  • Subscribers 38 subscribers
  • Views 582 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.

TIDA-010054: TIDA-010054

Upasana Sarma
Prodigy 100 points

Part Number: TIDA-010054

Hello,

I wish to know why the DC block capacitors are used in the converter circuit. I also wanted to know how to tune the values of these capacitors.

Thanks and regards,

Upasana Sarma

  • 0
    TI__Intellectual 1100 points

    Hello,

    DC block cap is needed to avoid unbalanced flux density seen by the transformer, which will result in magnetic saturation of the transformer. If prim and sec sides keep 50% duty cycle and only single phase shift across prim and sec is applied, which keeps volt-sec balanced, the converter can work w/o DC block cap. In case multiphase shift(duty cycle changes), the DC block cap is needed to achieve balanced flux density. Otherwise, a flux balancing control loop is needed by measuring the tank currents. The value of DC block cap is chosen based on the max power output and to have less current stress on the cap (that's why you see multiple caps in parallel) and the switching freq as well. 

    Regards

    Lei

  • 0 in reply to Lei Song
    Prodigy 100 points

    Thank you so much for your reply. However, what value of DC block cap do you suggest for 1kW, 100kHz switching frequency application?

  • 0 in reply to Upasana Sarma
    TI__Intellectual 1100 points

    Hello, 

    Theoretically, you can take 10 times smaller than TIDA-010054. Pls make sure the cap value you choose will not attenuate 100kHz switching freq. Pls run a simulation to prove it. 

    Regards

    Lei

  • 0 in reply to Lei Song
    Prodigy 100 points

    Thank you so much.