Forward voltage binned LEDs?

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treez

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The below (example LEDs '1' and '2') demonstrates that Forward voltage binned LEDs are always around twice as much in cost as otherwise equivalent non-forward-voltage binned LEDs.
Given this price difference, why do people use forward voltage binned LEDs?
I mean, LEDs are always put in series (most usually anyway) so forward voltage binning shouldnt matter?

1.....Cree, White, XPEHEW-L1-000-00BE7 = $1.54 (@ 5000 pces on digikey)

XPEHEW family datasheet:-
**broken link removed**



2.....Cree, White, MX6AWT-A1-0000-000BE7 = $0.77 (@ 5000 pces on digikey)

MX6AWT datasheet:-
**broken link removed**
 

What is a 'binned' LED?
 
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They are different devices. The only binning I can see is for brightness (efficiency). The range of forward voltage is the same in each case (0.5V). It is not uncommon for LEDs to be grouped by brightness but I have not seen it for forward voltage, although you may get a different forward voltage for the ones binned for brightness.

Keith
 
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Hello Treez, Voltage bin is different from LED to each other, so when you use low Vf you need less input voltage to drive LED, fo example if you have your input voltage 9V and you two LED bin voltage ( 2V and 2.5V) in that case if you want to put 4 LEds in series, you will be obliged to use 2V voltage Bin, and 2.5 voltage bin is not useful for you, that's why low Vf voltage bin is cheaper than high Vf voltage bin
 
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I also don't see a reference to voltage binning. Where did you find it?
 
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Rohitchampion said:
- - - Updated - - -



Binning is testing and sorting(according to properties) of LEDs.
Click to expand...
Then why not say 'sorted'. Everyone I know considers 'binning' to be throwing something away.
 
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pebe said:
Then why not say 'sorted'. Everyone I know considers 'binning' to be throwing something away.
Click to expand...

No. In electronics , binning is sorting into bins, not necessarily throwing things away. "Sorting" does not mean binning so the words aren't interchangeable. Bipolar transistors have been binned for hfe for as long as I can remember. You will even find binned Spice models for MOSFETs in IC design.

Keith.
 
That defies logic! I've been in electronics all my life and never heard of the term. In a factory environment, maybe.
 

Page 8 of the following explains the binning for the XPEHEW LED in the top post.

**broken link removed**

XPEHEW is a member of the XLamp family of LEDs.

LEDs are definetely available sorted in Vf bins...the question is, are Vf binned LEDs more expensive than LEDs which are similar but not Vf binned?
 

treez said:
LEDs are definetely available sorted in Vf bins...the question is, are Vf binned LEDs more expensive than LEDs which are similar but not Vf binned?
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That possibly depends on the Vf. Lower Vf LEDs are sought after by custom LED flashlight manufacturers because they are more power efficient. The flashlight will get more life from the battery, at the same brightness level.

Likewise the exact tint of white LEDs - neutral to warm tints are generally more desirable for colour rendering, but are rarer. That too is something the LEDs are sorted into bins for.

Often, real flashaholics will buy a lot of LEDs of a good bin, then sort them themselves into even finer levels to find the very best LED for their purpose.

Can you tell I use LED flashlights a lot?
 
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The order code at Digikey (identical to the oder code shown on page 2 of the XPEHEW data sheet) doesn't contain forward voltage information. So how do you know that diodes are sorted in bins? The feature might be available on special order only.

P.S.: My generally assumption is this:

The LEDs are always sorted into bins during production and it's guaranteed that all exemplars of a batch (e.g. a reel) have the same voltage bin. There's probably no option to order a specific bin, because the forward voltage can't be exactly adjusted during production. The manufacturer is targetting the center bin and don't know the distribution in advance.

This is a perfect question to ask a manufacturer's sales person, I think.
 
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It possibly is special order only. I have both Cree and Lumileds LEDs that I bought in specific Vf bins for upgrading flashlights.
 

This is a perfect question to ask a manufacturer's sales person, I think.
Click to expand...

Cree, Philips, Dialight, Avago, Osram-os................none of them ever answer this question. Ive asked many times.
 

Hi treez,
no the price will be expensive only if you ask supplier for sorting, but if you ask supplier for the part number ( that include many Vf bins) the price will be the same as.
 

but if you ask supplier for the part number ( that include many Vf bins) the price will be the same as
Click to expand...

....but by that do you mean i can buy a reel of leds whereby all the leds on that reel will be from the same voltage bin....but i cannot know in advance which voltage bin that will be?
...that is no good for us, we wish to put leds in parallel and must know exactly which voltage bin we buy from.......if it could be any bin in a certain range, then thats no good.

So in our case, where we buy all same voltage bin, i take it you mean this will be expensive for us.?
 

no don't worry about that, supplier will deliver one reel with the same soltage bin, and after that you have to put this voltage bin on the same board, so for the next reel the voltage bin can be different from the first reel ( but don't worry all voltage bin in a reel is the same), and you can know each voltage bin, for example OSRAM write on the reel the voltage bin for this LEDs
 
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Google for 'define bin' and you won't find a definition in any of the dictionaries there in the context that Cree use it. But then, Cree is an American company who never use an accepted word when a new one will do.

But I can now add that word to 'medicalize' that I learned last week!
 
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and you can know each voltage bin, for example OSRAM write on the reel the voltage bin for this LEDs
Click to expand...
...thanks but i thought your first explanation was more accurate...i.e. the reel code only tells you that the leds on that reel are Vf binned, and could be in any one of three voltage bins.....but you have no way of knowing which voltage bin that is?
 

.....but you have no way of knowing which voltage bin that is?
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In case of the Osram diodes, it's clarified in the datasheet that a bin code is printed on the reel and how it's coded.

Maybe it's the same with Cree diodes. I'm not not in the LED lighting business and had no motivation yet to find it out. I hear that you have apparently difficulties to get respective information from the manufacturers. I don't actually understand this kind of communication desaster...

At least the distributor who finally sells the product should know what he's shipping.
 
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