Ferrite inductor or Coil Inductor for Boost Converter

[SwissEngineer]

Hello Everyone,
I am designing a board and I need to choose the right inductor for my boost converter (TPS61220). The Vin is 3,6V and Vout 5,2V.
But my question is: Can I use a Ferrite bead as an inductor (http://www.digikey.ch/product-detail/fr/MLZ1608N4R7LTD25/445-17071-1-ND/4869871), I can't see the difference between a 4,7uH ferrite and a 4,7uH coil...

Thanks for the help

[krivx]

How much current are you looking for? It looks like that ferrite will saturate at only 80mA.

[SwissEngineer]

True... But why is the saturation current lower than the nominal? I wanted the maximum of the boost, so 400mA.

[RobK_NL]

I can't see the difference between a 4,7uH ferrite and a 4,7uH coil...

Well, I would suggest to look at the graph for "INDUCTANCE VS. DC BIAS" for that ferrite and then compare it to the graph for this coil:
http://www.digikey.ch/product-detail/fr/CIG22B4R7MNE/1276-6218-1-ND/3972136

Still don't see it? 

[SwissEngineer]

Okay just found the awnser.
A Ferrite will decrease the inductance as the current increases, so when the current is nominal, the inductance is null.
On the opposite, the Coil will keep the inductance until the saturation current. (See pictures below)

Conclusion (correct me if I'm wrong) : I can't use a ferrite instead of a coil with a boost converter

PS : I saw the graph before your reply  but thanks!!

[T3sl4co1l]

Ferrite beads are sold by small-signal impedance at some frequency, at zero DC.  (I'm amazed those TDK parts are even sold by inductance!)

They are not intended to function under DC bias (despite their typically generous current ratings, and frequent use in power supply rails).

Inductors are sold by inductance and DC bias.  (Conversely, they don't usually specify impedance at frequency, which makes it difficult to estimate efficiency.)

Inductors are made to store energy, ferrite beads are made to crudely filter (or dampen) small signal pins.

Shop accordingly

Tim