Achieve higher efficiency with MP8017

DC-DC Power Converters
1

We are trying to design a high efficiency PoE solution, 12V, 6W to13W out. After trying MP8017 evaluation board, it seems the output diode and the snubber is generating a bit of heat.

Ideally we’d like to replace both the input rectifier and output diode with active ideal diode rectifiers. Are there any recommended circuits from mps for ideal diode implementation of the output rectifier together with mp8017? Will it work with primary side regulation, (no opto-feedback)?

We have tried to hook the MP9989 evaulation kit up to MP8017 evaluation kit, replacing the output diode, but both the MP8017 and especially MP9989 seem to heat up excessively, especially the snubber circuits?

2

It would be interesting to see waveforms here of what the voltage and current of the secondary side look like. Since you are using evaluation boards, these are verified schematics.

If both the diode and MP9989 are both getting hot, then the problem must not be either of these. Waveforms would be good to diagnose if this has something to do with the way the MP8017 is being set up and if the input is stable.

3

Too much ripple or a short are some likely reasons as to why this could be happening. Check that there are no shorts when connecting these boards and ensure that the ripple here is at an acceptable level when acquiring the waveforms as asked in the earlier post.