David_
Advanced Member level 2
Hello.
I have a problem relating of the inconvenient sizes of inductors that can pass 40A, I am designing a buck-boost converter and size is one of the more important concern. But my calculations have indicated that I need a inductor that is at minimum 6,8µH and for other reasons I really don't want to go above the specified 25kHz that my converter are planned to switch at, not if it is avoidable.
I look at mouser for inductors and find that there are larger than what I had hopped especially since it looks like I am going to have to use two smaller inductors in series to reach the minimum 6.8µH, since the inductors that are so large(Henry wise) does have current ratings of...40A which is no good for passing 40A no?
So to get higher rated current I have to choose for example 3,3µH or 4,7µH, and I thought I should ask here if you think that it could be possible for me to construct a more space saving inductor my self or are those commercial components the smallest they can be?
Further more, in every example design I have looked at they calculate the inductor and if we pretend that the minimum value came out as 10µH then they are choosing something like 22µH or even 47µH, I know that they are deliberately choosing a much larger inductor but that behavioured makes me ask, is there any likely problem in using the calculated minimum inductor value for a buck or boost converter?
Regards
- - - Updated - - -
If you look at this, it has the required µH butnot the required current, while this has the required current rating while not the required µH rating. But two of those in series would almost make the value if assuming that the tolerances isn't negative...
There are others that are higher in µH but lower in current rating, such as this. Which would be rather expensive to use two of in series.
I have a problem relating of the inconvenient sizes of inductors that can pass 40A, I am designing a buck-boost converter and size is one of the more important concern. But my calculations have indicated that I need a inductor that is at minimum 6,8µH and for other reasons I really don't want to go above the specified 25kHz that my converter are planned to switch at, not if it is avoidable.
I look at mouser for inductors and find that there are larger than what I had hopped especially since it looks like I am going to have to use two smaller inductors in series to reach the minimum 6.8µH, since the inductors that are so large(Henry wise) does have current ratings of...40A which is no good for passing 40A no?
So to get higher rated current I have to choose for example 3,3µH or 4,7µH, and I thought I should ask here if you think that it could be possible for me to construct a more space saving inductor my self or are those commercial components the smallest they can be?
Further more, in every example design I have looked at they calculate the inductor and if we pretend that the minimum value came out as 10µH then they are choosing something like 22µH or even 47µH, I know that they are deliberately choosing a much larger inductor but that behavioured makes me ask, is there any likely problem in using the calculated minimum inductor value for a buck or boost converter?
Regards
- - - Updated - - -
If you look at this, it has the required µH butnot the required current, while this has the required current rating while not the required µH rating. But two of those in series would almost make the value if assuming that the tolerances isn't negative...
There are others that are higher in µH but lower in current rating, such as this. Which would be rather expensive to use two of in series.