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DC to DC Conveter

Swetha A M
Prodigy 70 points
Other Parts Discussed in Thread: UCC2809-1, TL431

Hi,

We need assistance for one of our requirement of “ DC to DC Converter “.

Where few of our required specifications are listed below

  1. Input voltage : 12 V.
  2. Output voltage : " -325 V "
  3. Ripple Vp-p : 10mV
  4. 3W output Power
  5. Approx. 1KV isolation

We request  to suggest any part if it meets the above requirements or any topology of the converter which can produce required output.

  • 0
    TI__Mastermind 29680 points
    Hello Swetha,

    Thank you for your inquiry. Someone will get back to you on this later today.

    Regards,
    Ulrich
  • 0
    TI__Mastermind 29680 points

    Hello Swetha,

    I suggest for you to consider using the UCC2809-1 PWM controller as illustrated in the PMP1511 reference design (which can be found on the TI website). This reference design is a similar, not exact, application to your description and can be used as a guide for your particular design.

    The transformer and components will need to be changed to match your output voltage. The polarity of the output is easily changed by grounding the positive rail instead of the negative rail. The TL431 control will be referenced to the negative rail. The auxiliary winding is used to bias the TL431 control and opto-isolator to reduce power loss. It is not absolutely necessary, as this biasing can be derived from the -325V output, but the power loss penalty is substantial. The winding helps to minimize this bias power. It will need to be referenced to the negative output rail. I suggest that this bias winding does not need to be 48V (which may have been a side application for the original reference design), but can be reduced close to 5 ~ 7V, so the turns-ratio can be changed accordingly.

    The ripple voltage requirement can be met by appropriate output filter design, and is not dependent on the choice of controller.
    If this answers your question, please check the “Verify Answer” box.

    Regards,
    Ulrich