Dear Sirs.

Attached is the image of buck drier, that drives laser diode with 2A current. I am designing the same type for which I am trying to find the inductor but unable to find.
the inductor required is 22uf. and I know it is good to select current rating little higher than laser diode current i.e. 2A.
Now in the image the inductor shown is 6.2mm diagonal and height is 2.4mm.
Can anybody tell me where to find this inductor?
when I tried in digikey when I select 22uf with current rating more than 2.6A I am not getting this size. I am getting big size inductors. Please tell me what is this confusion about and what I am missing. if in the driver he have selected current rating lower than the led current required?

 

the rthing that is confusing is that inductors are rated in Henrys, not Farads. 22uf is twenty two micro farad, a capacitor.

 

the rthing that is confusing is that inductors are rated in Henrys, not Farads. 22uf is twenty two micro farad, a capacitor.

oops sorry. I meant 22uH. sorry sorry.

 

Go to mouser.com, or digitkey, or one of the other major suppliers, and look for a 22 uH surface mount inductor. I took a quick look and there were over 1300 choices. Without knowing more about the design, it's hard to say what you need, exactly.

 

You can't build a 2 amp inductor with 30 gauge wire. Whatever you arrive at, it will have significant mass.

 

yes I want 22uH inductor and 2A current will be flowing into it. I want the size to be 6mmx6mm and height like 2.4~3mm.

 

You can't build a 2 amp inductor with 30 gauge wire. Whatever you arrive at, it will have significant mass.

S0 can I choose less current rating even though 2A current passing through it.
if I select 22uH of 1.6A instead 22uH of 2A current. what will happen?

 

look at this datasheet. in page 4. they have mentioned 22uH inductor. what current rating I have to select for the inductor?
that is for 1A output current. if I want to use the same circuit for 2A current. how much current rating inductor I have to select?

 

you need higher rating since pulses will be higher.

By the way these are quite common just dont take a too small kind- it will just get hot

 

S0 can I choose less current rating even though 2A current passing through it.
if I select 22uH of 1.6A instead 22uH of 2A current. what will happen?

If an inductor is used at above its rated current, most likely the inductance seen will be less than the marked rating. Between 1.6A and 2A, the circuit might still work fine. In fact, the original part might be rated for 1.6A. If this is your own design, I'd say try several different parts and see how they do.

 

It is all about selecting an inductor that will never saturate due to the peak current through it. The peak current in the inductor is much higher than the average LED current.

 

This looks very close to the one pictured. http://uk.farnell.com/epcos/b82464g4223m/inductor-22uh-20-2-25a-13mhz/dp/7429460