• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 562 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.

LM5045 Evaluation board (AN-2111)

Oleg Ayranov
Prodigy 20 points
Other Parts Discussed in Thread: LM5045

Is it possible to modify the LM5045 Evaluation board (AN-2111) for higher output voltages, e.g. 36VDC?

Which components on the board should be changed?

Does it make sense to use synchronous rectifiers for an output voltage of 36V instead of schottky diodes? 

Is it possible to use the intern high voltage startup regulator of the LM5045 all the time? If yes, how much will decrease the overall efficiency?

  • 0
    TI__Mastermind 34465 points
    Yes it is possible to re-design the LM5045EVM for a 36V 2.8A output.
    You will need to redesign the transformer T1.
    Increase the secondary turns ratio by a factor of 10 and decrease the auxiliary turns proportionally so that the bias power remains at about 5V or so.
    Its probably best if you contact a transformer manufacturer such a Wurth Midcom and they will be able to help you with the transformer design.
    Synchronous rectification is not needed at 36V and a planar transformer is not required at 2.8A.
    You will need to adjust the feedback resistor R29.

    John Griffin
  • 0 in reply to John Griffin1
    Prodigy 20 points

    Thank you for the fast response.

    Now a few other questions:

    I would like to draw more curret from the 36V output, e.g. 10A. In the AN 2222 there is a 720W Application with 2 parallel MOSFETs IRF5053 in every leg of the H-bridge. The board has no heat sinks. Does it mean I can have half the power (360W) with the same layout but only one IRF5053 in every leg?