Identify inductor in Atmega32u4 circuit

Thread Starter

pedro147

Joined Jan 1, 2013
52
I am trying to recreate this circuit from the schematic and am trying to identify the component labelled L1. From the Eagle part library description it is a NR301X Package of Value 2.2 uF 3 x 3mm inductor. I found this product in a general sense here http://elcodis.com/searchparts/nr301.html but was hoping someone here might offer me as positive an educated guess as to exactly what part it is seeing as the circuit is pretty generic for this type of flight control board for radio controlled quadcopters. A link to an appropriate part if possible would be great. Thanks for any possible help or advice Pedro.

The Eagle circuit con be viewed or downloaded here http://www.mediafire.com/view/50j9z22888u0jg8/AW.sch
 

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Papabravo

Joined Feb 24, 2006
21,225
Looks like a tall order since the symbol implies an inductor and the value implies a capacitor. Whoever drew that schematic didn't know his elbow from third base. Maybe he meant microhenries or millihenries. Who really knows without redoing the design. Do you have the chops for that?

You might want to start with a datasheet for the switching regulator.. I believe from the part number it should be a part from TI (Texas Instruments).
 

Thread Starter

pedro147

Joined Jan 1, 2013
52
Thanks for the reply Papabravo. "Do you have the chops for that?" Short answer no way :) I know someone who has just replaced that buck boost converter so if I was to get a data sheet for it would you be able to work out the value of that inductor for me please. From what I have see it definitely is an inductor as opposed to a capacitor and I have attached an image of the part for reference. There are unfortunately no discernible markings on the component to help ID it.


Alienwii closeup - L1 Inductor.jpg
 

Thread Starter

pedro147

Joined Jan 1, 2013
52
Thanks Nerdegutta, I just saw your reply then. I am a bit slow on the uptake today :) So seeing as I amt trying to generate an Eagle board file from this schematic, and the part library package will have the pad measurements for the correct chip, is it just a matter of comparing that to the mechanical drawing of some of these inductors until I find one that has exactly the same footprint. Do you think that this one may be a good candidate or isn't there enough information to make an informed choice. Sorry for being so vague but I am well outside my skillset here http://elcodis.com/parts/1253210/NR3010T2R2M.html#datasheet
 
Last edited:

nerdegutta

Joined Dec 15, 2009
2,684
I think that it would be ok, but you need to double and tripple check the footprint. And you need to check what the datasheet for the TPS has to say about what type of inductor the IC needs.
 

Thread Starter

pedro147

Joined Jan 1, 2013
52

Papabravo

Joined Feb 24, 2006
21,225
I'm glad you were able to resolve your problem. It is unfortunate that there is stuff on the internet with sloppy mistakes such as this. You were wise to post the question as you could have wasted hours looking for 2.2 μF inductor. Even if you do not "have the chops" to do a design from scratch today, it is certainly within your grasp. Good luck on your project.
 
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