Alternate Inductor that can be used for MT3608 boost converter circuit

Question

I am planning to use MT3608 schematic for my project to boost the voltage from 3.7V to 5V. I am planning on making a customized PCB with all the requirements that are needed for the project.

In the MT3608 module, which is available mostly in the outside market, the inductor used is 22uH. Below are the MT3608 module and the Inductor component that is used in the MT3608 module. Link to the Inductor component

However, it is difficult to procure this component as it is not that frequently available everywhere. In the datasheet, they have mentioned the inductor specifications as seen in the image below.

Can I use any other Inductor of same value of 22uH? Or is there an exact alternative that can be used for this component?

It will be helpful if I can get a component that can be used instead of this one.

Thanks in advance.

Answer 1

Can I use any other Inductor of same value of 22uH?

No -- in fact, that "Inductor Selection" thing that you quote is pretty specific that the series resistance and core loss matter, as well as the inductance.

Or is there an exact alternative that can be used for this component?

The three things that matter the most are the series resistance, the core loss, and the saturation current. If you can get your hands on a datasheet for that inductor, then go looking for inductors available more locally to you (i.e. TDK, MuRata, etc.)

If you have a favorite distributor, look through their catalog. Chances are that an inductor in the same package with the same value will work, but you really want to double check the specifications.

Answer 2

I know what you're asking, basically are there any equivalents or alternatives to the inductor choices that fall within the criteria of the datasheet and where i do humbly think, personally, that this info will further benefit ANYONE/as many as possible when they also read this answer, so not only for the original question post's author, but i surely hope everyone too, here goes:

So as per your "Inductor Selection" Snippet you used from the datasheet (AeroSemi?) for the Step down converter MT3608, which tells us the important criteria we need to search with, being an inductor of:

1. Low Core Loss at 1.2 MHz
2. Low 'DCR' for better efficiency
3. 22 uH value

So i just went to Mouser UK (International Company & this is being used just as an example of how to search for one's own self, use whatever you feel comfy with) So search for the exact or close-enough characteristics of the inductor we need for these projects and I've found 14 results in the list after narrowing it down but only using what info is specifically in that Datasheet snippet above, here's 2 pictures from screenshots from me own desktop to further illustrate how to better search for exactly what you need and asked for, or be in the ball-park for better choice options than without these sort of searching:

And second picture here:

The actual results page of the Mouser web-search so you don't have to go through that yourself is here:

Mouser Results

Took me a WHILE to get this all down as I'm dyslexic so please do expect a few mistakes here & there by me, lol, but i hope this helps with component selection going forwards from specific data laid out in the manufacturer's datasheets to have a lot more options available to those whom love making their own PCB's

Now - sadly Mouser doesn't have that low an inductance inductor of 22 uH, which was the whole point of the searching, which is also quite darn-difficult to find for people INCLUDING ME, and as the results show, the lowest inductor in the searched results on that mouser webpage is 680 uH WHICH IS NOT WHAT WE WANT !!! (don't worry, this sorta stuff drives me crazy too, haha)

So on a different website, hopefully like Digikey, if you run this search again but on a different website for IN STOCK items only, then hopefully you'll have better luck, but the pre-ordering times are not really that bad for out of stock items, which if you do this search again on the 14 results page and INCLUDE out of stock items too, I'm sure we would get a 22 uH inductor (as I'm also BIASED towards liking SMD components more than Through-Hole (TH))

Answer 3

22 uH is a relatively high value for this circuit. It will run in continuous conduction mode at relatively light output load.

Higher inductance will reduce the peak output ripple current resulting in lower output voltage ripple for given output filter capacitor.

Higher inductance stores more micro-joules of energy in coil.

Downside of larger inductance is it requires inductor core capable of handing the core saturation of more turns of wire on the core. Also there will likely be more resistance due to longer wire length for winding resulting in lower efficiency.

Depends on what output voltage and current you need.