Where is the bin code/label of LED


Recently I have purchased 150 LEDs from Digi-Key and expected bin code/label of the batch to be on the package.

But I can't find it?

Where do I find bin code/label information?

Best Answer

Since the distributor won't respond (I really think they should take the effort to reproduce such information from the label on their labels- we've found them quite responsive to such suggestions at least for future orders), you're kind of up the creek. Their responsiveness may be less if you've not been placing lots of good size orders, of course.

Chances are high that if they're in an unbroken string of cut tape that they're all the same bin for luminous intensity (brightness at the test current of \$I_F = \$5mA). There is no way to tell which one without some sophisticated photometry equipment, unless you have some parts of known brightness (and preferably exactly the same color) that you could compare them to. The forward voltage bin you can measure easily, but I don't think that's particularly useful.

Usually you don't (or shouldn't) care much about the brightness bin except for matching (you might be making a display that uses many side-by-side that would look cruddy if they were all different brightnesses at random), unless you've paid a premium to get the really bright ones.

There's really no 'best' voltage - you just run them at your design current (hopefully a conservative one) and you get what brightness you get, with a somewhat variable forward voltage. If you run too high a current, they fade quickly, or fail on a hot day (or even immediately), if you run too low a current they look.. dim. If you buy the right LEDs for the job there's a nice fat region where they're bright enough but running at a reasonable current. These ones (regardless of bin) are 11.5 to 28.5mcd @5mA, which is reasonably bright and a reasonably tight spec.

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