• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 3 answers
  • Subscribers 62 subscribers
  • Views 329 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.

Original question:

UCC256301: LLC Resonant converter for variable power supply design

UCC256301: LLC resonant

aash mohd
Intellectual 630 points
Part Number: UCC256301
Other Parts Discussed in Thread: LM317, TL103W

hi,

I am new to LLC resonant bridge convertor design .

I am confused to how control current and voltage individually for example

at time t0 , i want a voltage say 44V and current 30A

and at time t1 , i want voltage say 54V and current 10A

in this  LLC resonant half bridge convertor design

Thank You.

  • 0
    TI__Expert 8210 points

    Aash

    Like all switched mode power supply designs, only one parameter can be regulated at a time thru the feedback network.  For most designs this is the output voltage.  The current is set by how much the load draws.

    If you would like to design a power supply that varies regulation between voltage and current (such as regulate voltage until a certain power level, then regulate current and let the output voltage drop) a CV/CC feedback network is needed.  TIDA-010038 is an example design that uses a resonant LLC converter in such a configuration.

    Best Regards,

    Eric

  • 0 in reply to Eric Faraci
    Intellectual 630 points

    Hi Eric

    Thanks for the quick response!

    By this line: 

    "if you would like to design a power supply that varies regulation between voltage and current (such as regulate voltage until a certain power level, then regulate current and let the output voltage drop) a CV/CC feedback network is needed"

    you trying to say, i can control both Current and voltage individually in LLC converter ? if yes then how?

     Thank you.

  • 0 in reply to aash mohd
    TI__Expert 8210 points

    Aash

    You can control current OR voltage.  You can use diode circuit to create OR circuit that will allow for regulation of output voltage or current, but you cannot regulate both parameters at the same time.

    In TIDA-010038 this circuitry is in the circuitry under TL103W, INA180A and LM317 in the simplified schematic block diagram on page 1 of the schematic https://www.ti.com/lit/df/tidrxu2a/tidrxu2a.pdf?&ts=1589416611553

    Best Regards,

    Eric

  • 0 in reply to Eric Faraci
    Intellectual 630 points

    Thanks alot Eric!

    But my doubts still exists like-

    If i have a load of fixed If i have a load of fixed current 25A

    And i want to change Voltage from 12V to 16V

    How can i achieve this?

    Similarly,

    If i have a load of fixed voltage of 12V  

    And i want to change current from 10A to 25A

    How can i achieve this?

    By using LLC resonant half bridge convertor?

    And also, if i changes LLC switching frequency  both output voltage and current changes.

    So how can i able to change one parameter at a time as mentioned above.

  • 0 in reply to aash mohd
    TI__Expert 8210 points

    Aash

    You can adjust the output that is regulated by adjusting the feedback circuit.  This is typically done by adjusting the reference voltage.  If the converter is regulating the output voltage this allows you to adjust the output voltage, and if it is regulating the output current it allows you to adjust the output current.

    In the example design TIDA-010038 from earlier, you can adjust the reference voltage by adjusting the trimpot resistor R42 resistance.

    I also recommend that you review the following videos to further answer any questions you have https://training.ti.com/power-management-fundamentals.  This book may also have further information you may find helpful http://www.ti.com/tool/PWRSUPPLYBOOK

    Best Regards,

    Eric