Hi,
I guess others had the same problem before.
Hint:
* look at he box below "Similar threads"
* do an internet search and find 6 million of results.
6 million is a bit too much to read them all. So what to do next:
* Usually at the first page of the results there are good documents. you may go through a couple of them.. to find out what new questions arise.... for a new - more detailed internet search.
* Or you may go to semiconductor manufacturers for DCDC converters or chip manufacturers. They usually provide very good informations, calculations, design notes, application notes, software, videos. You can rely on them - (this is not random hobbyists information, like most of the internet search results)
This will give you more information than all we can write in this thread.
But we are here if you have more detailed questions.
For more detailed answers we need way more informations than "30kHz". But the above mentioned documents will show you...
Klaus